Alternating-Treatments Design in Sport and Exercise PDF

8 The alternating-treatments design in sport and exercise In this chapter, we shall: outline the rationale underlying the use of alternating-treatments designs in sport and exercise; outline variations of the alternating-treatments design; provide guidance on using this design in applied sport and e...

8 The alternating-treatments design in sport and exercise In this chapter, we shall: outline the rationale underlying the use of alternating-treatments designs in sport and exercise; outline variations of the alternating-treatments design; provide guidance on using this design in applied sport and exercise contexts. Case example Eric is an eighteen-year-old tennis player who despite his natural technical skill lacks the necessary mental skills to deal with pressure and maintain confidence and concentration during tournament play. Despite his apparent lack of mental skills, Eric is motivated to be successful in tennis and regularly participates in an intensive training regime. However, when asked to undertake tasks (by his coach) that require independence (e.g., keeping a reflective training diary) Eric often struggles with the challenge and forgets to complete the tasks. Based on recommendations from his coach, Eric has recently undertaken work with a sport psychologist in an effort to improve his mental skills in tennis (using positive self-talk, imagery and goal-setting). The sport psychologist, although pleased with Eric’s mental skills development, is somewhat concerned by his lack of motivation in practising his mental skills in his own time. 126â … The alternating-treatments design in sport and exercise Introduction and basic rationale for the design Applied behavioural researchers and practitioners are increasingly expected to draw upon evidence-based practice when using interventions with clients or client groups (e.g., Barlow et al. 2009; Hemmings and Holder 2009). To this end, interventions must be selected by practitioners on the basis that research has deemed them effective relative to a particular issue and/or client or group. Traditionally, nomothetic (see also Chapters 1 and 10) research paradigms have been adopted to identify effective interventions in which large-group studies are used to draw inferences about participants’ reactions (e.g., mean responses of a treatment group are compared with mean responses of a control group; Barker et al. 2010). In these research paradigms, comparisons are made between groups and hence inferences about individuals are extrapolations from group data. There are many benefits of using nomothetic research designs. For example, such designs permit the development of principles, laws or global understanding, allow for prediction and have high external validity (Clark-Carter 2009). However, nomothetic research designs often mask individual reactions and responses to interventions (i.e., idiosyncrasies), information that is important to practitioners and researchers working with individual clients and/or client groups. Indeed, this information is often important for the development of the intervention protocol (Hanton and Jones 1999) as well as making conclusions about intervention efficacy and effectiveness (Seligman 1995). Typically, the researcher and practitioner in applied settings is not interested in comparing mean scores from treatment and control groups but is concerned with an individual’s response to an intervention over time. Therefore, single-case designs are attractive options to applied investigators because they enable individual reactions and responses to be studied through intra-subject, time-series comparison (Kazdin 1982). A common feature of applied settings is the fact that, whereas a given intervention may work for one client, it may not work for another – and hence an alternative intervention programme may have to be prescribed. Therefore, identifying effective interventions in applied research may also involve comparing treatments (Barlow et al. 2009). For example, when a practitioner has identified (through baseline measures) the target variable to be treated, guidance is often taken from an array of literature supporting more than one potential intervention strategy relative to the target variable. In this instance, the practitioner may take a pragmatic view and choose to use two treatments (both of which are supported in the literature) to see which is more effective (i.e., to which the participant responds best). In single-case terms, this type of design is described as an alternating-treatments design (ATD). In this chapter we first consider the main tenets of the ATD before exploring examples from the literature. We then consider ATD design variations before providing an overall critique of the design. The ATD design (first described by Barlow and Hayes 1979) involves The alternating-treatments design in sport and exerciseâ … 127 systematically alternating two or more interventions across time and comparing relative responses of the target variable to each intervention (Kratochwill et al. 1984). Moreover, the ATD allows a participant to be exposed to separate treatment conditions for equal periods of time. To this end the ATD has been defined (Barlow and Hayes 1979) as a between-series design because one is comparing results from two or more separate series of data points. In the ATD, treatments are alternated for a brief period (e.g., treatment A is administered in one session and treatment B in another session). Alternation of the treatments is established by either counterbalancing or randomly assigning treatments across phases of the study (Barlow and Hayes 1979). The ATD design originates from a group of experimental designs common to the study of operant behaviour in applied settings. These designs include the multiple-schedule design (Hersen and Barlow 1976; Leitenberg 1973), simultaneous-treatment design (Kazdin and Hartmann 1978) and the multielement design (Ulman and Sulzer-Azaroff 1975) and were used to identify relationships between behaviour and stimulus events in learning experiments (e.g., McGonigle, Rojahn, Dixon and Strain 1987). These designs share the feature of rapidly changing experimental conditions with similar stimuli associated with different conditions. As we will see in the forthcoming sections, the ATD is an extremely flexible and adaptable design, sharing many features with other single-case designs already described in this book. Interestingly, the collection of baseline data is not a requirement of the design (because of clinical or practical concerns) although, when collected, data serve the same purpose as in previous designs: namely to illustrate the natural state of the target variable and to allow comparison between baseline and treatment responses (Wacker et al. 1990). Inferences about treatment effectiveness in the ATD are a result of the rapid phase changes that occur as interventions are alternated. Moreover, when variable change tracks the rapid phase or treatment changes (i.e., baseline to treatment, or treatment A to treatment B) a treatment effect is observed, making the effect of extraneous variables unlikely (Barlow and Hayes 1979). To illustrate, you may recall Eric our tennis player from earlier in the chapter who was working with a sport psychologist to develop his mental skills but who was erratic in his adherence to self-practice routines. Remember how the sport psychologist asked Eric to document daily adherence records (i.e., minutes of daily self-practice) for five consecutive days. The daily number of minutes that Eric spent practising his mental skills during the baseline is depicted in the first panel of Figure 8.1. From this figure it is evident that the amount of self-practice fluctuates on a daily basis, thus supporting the sport psychologist’s conclusion about Eric’s erratic adherence rate to his practice routine. Following baseline, the sport psychologist then introduces two treatments (treatment A: email reminders; treatment B: SMS text alerts) on alternative days during an intervention phase to encourage Eric to practise his mental skills. To illustrate, on day six the sport psychologist sent Eric an email (treatment A) after his morning training session at 10â ›a.m. to remind him to engage in self-practice. 128â … The alternating-treatments design in sport and exercise !"#$%&'()*(+,"-.(!&#%,-(/0"--'(12,343&( &"! 4/5.672.8! 9:;0-./01.20! %#! %"! ,-./01.20!4! $#! $"! ,-./01.20!3! #! "! $! %! &! '! #! (! )! *! +! $"! $$! $%! $&! $'! $#! $(! $)! $*! $+! %"! /$33&''"5&(+,.'( !! Figure 8.1â ‡Hypothetical data from an ATD design containing several subphases during the intervention. Subsequently, on day seven, the second treatment (B) was instigated in which the sport psychologist sent Eric an SMS text alert following his training session at 10â ›a.m., again reminding him of his self-practice. These two conditions were then alternated daily for two weeks. These hypothetical data are illustrated in the second panel of Figure 8.1 and demonstrate the amount of time (in minutes) spent engaging in self-practice. Each line in this phase represents adherence to mental skills training under a specific treatment condition, in this case email or text reminders. Interestingly, it is noticeable how data points for each treatment are reported on alternative days and this represents the essence of the ATD design. Overall, the data clearly indicate that treatment B was more effective than treatment A in increasing the amount of time Eric spent self-practising his mental skills. Therefore, in such situations in which the most effective intervention is evident, the practitioner or researcher will often discontinue the least effective treatment and continue a course of intervention involving the effective strategy (Barlow and Hayes 1979). The use of ATDs in applied research has increased since Kazdin (1982) suggested that they were the least underused single-case design (see Holcombe, Wolery and Gast 1994; Kinugasa et al. 2004; Strømgren and Kolby 1996). The literature now boasts over 700 research reports applying the ATD or design variations comparing the effect of treatment and no treatment (baseline) or comparing two or more distinct treatments (Barlow et al. 2009). The rest of this section provides examples from the literature illustrating these strategies of the ATD. The alternating-treatments design in sport and exerciseâ … 129 The research literature contains many examples of studies comparing treatment and no treatment using an ATD (e.g., Jordan, Singh and Repp 1989; O’Brien, Azrin and Henson 1969). Ollendick, Shapiro and Barrett (1981) conducted a notable study using an ATD to compare treatment and no treatment conditions. Specifically, the study compared the effects of two treatments (i.e., physical restraint and positive practice overcorrection) with no treatment (i.e., continued baseline) in the reduction of stereotypic behaviour in three children with severe intellectual disabilities. The target variables of the study involved bizarre hand movements (e.g., hair twirling and hand posturing). The study comprised the administration of three fifteen-minute sessions each day by the same experimenter. Following the collection of baseline data for all three time periods, the two treatments and the no treatment were issued in a counterbalanced manner across the sessions. During the sessions, each participant was positioned at a small table in a classroom and instructed by the experimenter to work on one of several visual motor tasks. Treatment one (physical restraint) consisted of a verbal warning and manual restraint of the participant’s hand on the tabletop for thirty seconds on the presentation of the stereotypic behaviour (e.g., hair twirling). Treatment two (positive practice overcorrection) consisted of the same verbal warning but was subsequently followed by manual guidance in appropriate manipulation of the task materials for thirty seconds. The no treatment condition consisted of an extended baseline in which the experimenter monitored behaviour occurrence and task performance. Throughout the study data were collected on the total number of stereotypic behaviours during each session and performance on the visual motor tasks. Importantly, in this study when one of the treatments produced a zero or near-zero rate of stereotypic behaviour that treatment was then selected and presented across all three time periods for the remainder of the study. Data collected from two of the study’s participants are illustrated in Figures 8.2 and 8.3. Data collected for John in Figure 8.2 demonstrate physical restraint to be the most effective treatment, whereas, in contrast, data for Tim (Figure 8.3) reveal positive practice to be the most effective. In contrast to the above illustration of an ATD comparing treatments with no treatment, the following example typifies the common application of the ATD in comparing the relative effects of two or more relevant treatments. To illustrate, in their study Agras, Leitenberg, Barlow and Thomson (1969) evaluated the effects of social reinforcement in the treatment of a fifty-year-old hospitalized women suffering from claustrophobia. This participant was unable to remain in rooms with doors closed, lifts or cinemas, or spend long periods of time in a car. Her fears had intensified following the death of her husband seven years earlier. Baseline data consisted of asking the participant to sit in a small windowless room and monitoring the length of time it took until she became uncomfortable. This process was replicated four times each day (block of trials). Following baseline, the two therapists worked with the participant to help her become more comfortable being in the small windowless room. Typically, each day both 130â … The alternating-treatments design in sport and exercise Alternating Treatments Task Performance per Session Hair Twirling per Session Baseline 10 9 8 7 6 5 4 3 2 1 0 70 60 50 40 30 20 10 0 Physical Restraint John No Intervention Positive Practice Physical Restraint 0 5 10 15 20 0 5 10 Sessions 15 20 Figure 8.2â ‡ Stereotypic hair twirling and accurate task performance for John across experimental conditions. The data are plotted across the three alternating time periods according to the schedule that the treatments were in effect. The three treatments, however, were presented only during the alternating-treatments phase. During the last phase, physical restraint was used during all three time periods. Adapted with permission from T. H. Ollendick, E. S. Shapiro, R. P. Barrett (1981) Reducing stereotypic behaviors: An analysis of treatment procedures utilizing an alternating treatments design. Behavior Therapy, 40, 570–577. therapists worked with the participant for two sessions each. One therapist provided praise when the participant increased her time in the room, whereas the other maintained a friendly relationship with the participant without presenting any praise. The ATD, therefore, compared the two treatments of contingent praise versus no praise, and investigated whether or not the participant could discriminate between the different therapist–intervention combinations. Data were collected on the time in seconds that the participant spent in the room across the phases of the study. In the first intervention phase time spent in the small room was increased with the therapist who provided reinforcement (RT) in comparison with the therapist who provided no reinforcement (NRT). In phase two of the intervention the therapists changed roles (i.e., the person who provided RT provided NRT and vice versa) and data indicated that the participant discriminated between the therapists and therefore performance was The alternating-treatments design in sport and exerciseâ … 131 Alternating Treatments Task Performance per Session Hair Twirling per Session Baseline 20 18 16 14 12 10 8 6 4 2 0 20 18 16 14 12 10 8 6 4 2 0 Positive Practice Tim No Intervention Positive Practice Physical Restraint 0 5 10 15 20 0 5 10 Sessions 15 20 Figure 8.3â ‡Stereotypic hand posturing and accurate task performance for Tim across experimental conditions. The data are plotted across the three alternating time periods according to the schedule that the treatments were in effect. The three treatments, however, were presented only during the alternating-treatments phase. During the last phase, positive practice overcorrection restraint was used during all three time periods. Adapted with permission from T. H. Ollendick, E. S. Shapiro, R. P. Barrett (1981) ‘Reducing stereotypic behaviors: An analysis of treatment procedures utilizing an alternating treatments design’, Behavior Therapy, 40: 570–577. maintained with the therapist providing praise. In the third and final phase the therapists returned to their initial roles and the participant again discriminated between them. In sum, data indicated that the participant remained in the room for longer when she consulted with the therapist who provided reinforcement. Another more recent example of comparing the effects of two or more treatments is provided by Rhymer, Dittmer, Skinner and Jackson (2000), who used an ATD to evaluate the effectiveness of an educational programme that combined timings (using chess clocks), peer tutoring (i.e., peer-delivered immediate feedback), positive practice overcorrection following errors, and performance feedback on mathematics fluency (i.e., speed of accurate responding) in four 132â … The alternating-treatments design in sport and exercise elementary students with mathematics skills deficits. Experimental conditions consisted of a baseline in which students completed three maths sheets (A, B and C) comprising multiplication problems. In this phase they were instructed to complete the sheets as quickly as possible, in a one-minute time phase. The time in seconds taken to complete the sheets was then recorded. During the intervention phase, students were placed in a dyad and had a chess clock that was set to two minutes. Three sets of multiplication problems (A, B and C) were assigned to one of three conditions (tutee, tutor and control). For example, for student 1, set C was assigned to the tutee condition (i.e., in which students were paired and took turns responding), set B to the tutor condition (i.e., in which students were paired and provided positive practice overcorrection feedback following an incorrect answer) and set A to the control condition (i.e., in which no practice of the problems had taken place). Following completion of the above procedures on five separate occasions, an assessment performance feedback phase was added. Typically, before each maths assessment, students were told their highest number of correct problems per minute regardless of which set of problems was being assessed (A, B or C). Moreover, students were encouraged to try and beat their record during subsequent assessments. Finally, six and seven weeks after the last intervention session, two further assessments were conducted to assess the maintenance effects of the interventions. During these assessments, each set of problems was assessed in random order. Data as illustrated in Figures 8.4 and 8.5 depict the number of problems correct per minute for the four students across the phases of the study. Specifically, the data indicate that serving as tutee and as a tutor, and receiving assessment performance feedback, resulted in initial and maintained increases in maths fluency for three of the four students (1, 3 and 4). In addition, none of the students showed improvement on the control set of problems. Overall, the ATD is useful and appropriate when a researcher or practitioner is concerned with comparing treatments with no treatment or with comparing two or more treatments with the same participant. Rapidly alternating the treatments allows for multiple comparisons of the target variable(s) responses under different treatment conditions (Holcombe et al. 1994). The illustrations in this section demonstrate how the ATD has been used in applied behavioural research. The following section explores research using the ATD in sport and exercise settings. The alternating-treatments design in sport and exercise: illustrations Numerous examples of the ATD can be found in mainstream applied behavioural research (e.g., Barlow et al. 2009); however, in the sport and exercise literature this trend is less obvious (Kinugasa et al. 2004). For example, Hrycaiko and Martin (1996) reported that, since an initial publication in a sport setting by McKenzie and Liskevych (1983) comparing the effects of three different The alternating-treatments design in sport and exerciseâ … 133 Intervention Package Baseline 35 Intervention Package and Assessment Performance Feedback Maintenance Student 1 Number of Problems Correct per Minute 30 25 Control Tutee Tutor 20 15 10 5 0 4 1 10 13 19 16 Sessions Intervention Package Baseline 35 22 25 28 31 Intervention Package and Assessment Performance Feedback Maintenance Student 2 30 Number of Problems Correct per Minute 7 Control Tutor Tutee 25 20 15 10 5 0 1 4 7 10 13 16 19 Sessions 22 25 28 Figure 8.4â ‡ Number of problems correct per minute for students 1 and 2. From K. N. Rhymer, K. I. Dittmer, C. H. Skinner and B. Jackson (2000) Effectiveness of a multi-component treatment for improving mathematics fluency. School Psychology Quarterly, 15, 40–51. American Psychological Association. Adapted with permission. treatments to improve per cent accuracy of setting in volleyball, not a single article published in the Journal of Sport and Exercise Psychology (1979–1994), The Sport Psychologist (1987–1994) or Journal of Applied Sport Psychology (1989–1994) had used the ATD design. Furthermore, a recent and broader search of the sport and exercise and applied behaviour journals has yielded only a few additional publications of the ATD in the contexts of sport and physical education. In our first example, Wolko et al. (1993) used an ATD in a sport setting to compare the effects of standard coaching (i.e., baseline condition) with those of standard coaching plus public self-regulation (i.e., self-controlling emotions, 134â … The alternating-treatments design in sport and exercise Intervention Package Baseline 35 Intervention Package and Assessment Performance Maintenance Feedback Student 3 Number of Problems Correct per Minute 30 25 Control Tutee Tutor 20 15 10 5 0 4 1 10 13 16 Sessions Intervention Package Baseline 35 19 22 25 Intervention Package and Assessment Performance Feedback Maintenance Student 4 30 Number of Problems Correct per Minute 7 Control Tutor Tutee 25 20 15 10 5 0 1 4 7 10 13 16 19 Sessions 22 25 28 Figure 8.5â ‡ Number of problems correct per minute for students 3 and 4. From K. N. Rhymer, K. I. Dittmer, C. H. Skinner and B. Jackson (2000) Effectiveness of a multi-component treatment for improving mathematics fluency. School Psychology Quarterly, 15, 40–51. American Psychological Association. Adapted with permission. behaviours and desires; treatment 1), against standard coaching plus private selfregulation (treatment 2) on the frequency of successfully completing gymnastic beam skills (nâ ›=â ›five gymnasts). Each condition lasted for six sessions, with the conditions being randomly alternated across eighteen sessions. Data presented for one of the gymnasts in Figure 8.6 reveals self-regulation (treatment 2) to be the most effective intervention. Overall, data demonstrated that treatment 2 was more effective than treatment 1 in three of the five gymnasts, whereas one of the gymnasts showed mixed results relative to the effects of the interventions (i.e., The alternating-treatments design in sport and exerciseâ … 135 105 Baseline × Treatment 1 Treatment 2 Number of Completed Skills 90 75 × 60 × 45 × 30 15 0 × × 1–3 4–6 7–9 Sessions 10–12 × 13–15 16–18 400 350 Cumulative Number of Completed Skills 300 250 × 200 × 150 × × 100 × 50 × 0 0 1–3 4–6 7–9 Sessions 10–12 13–15 16–18 Figure 8.6â ‡Frequency of completed beam skills for a gymnast under conditions of standard coaching (baseline), standard coaching plus self-regulation (treatment 1), versus standard coaching plus private self-regulation (treatment 2). Each condition was in effect for six sessions, with the conditions randomly alternating across a total of eighteen sessions. The top panel shows the data plotted as a frequency graph, and the bottom panel shows that same data plotted cumulatively across sessions. This graph was adapted from data presented by Wolko, Hrycaiko and Martin (1993). Adapted from D. Hrycaiko and G. Martin (1996) Applied research studies within single-subject designs: Why so few? Journal of Applied Sport Psychology, 8, 183–199 (Taylor & Francis Ltd, http://www. informaworld.com) by permission of the publisher. treatment 1 was most effective for frequency of attempted skill and treatment 2 was most effective for frequency of completed skill). A more recent example of the ATD in a sport setting is provided by Lambert, Moore and Dixon (1999). These researchers investigated the relationship 136â … The alternating-treatments design in sport and exercise between two different types of goal-setting strategies (i.e., self-set and coach-set goals) and locus of control (i.e., the perceived location of the source of control over one’s behaviour – namely internal agency or external agency) with the dependent variable being ‘on-task’ behaviour (e.g., the frequency with which particular exercises would be completed during training sessions on the beam). Four female level eight and nine gymnasts (aged twelve or thirteen) were selected to take part in the study, two with an internal and two with an external locus of control. Using the ATD, participants were exposed to both goal-setting conditions. In the self-set goals condition, participants noted three self-generated goals concerning practice on the beam. In the coach-set goals condition, the coach assigned three goals relative to beam practice without consulting the participants. When clear and stable differences in the data collected under the two treatment conditions became apparent, a second phase was implemented (i.e., after twelve sessions, at which point a clear and stable separation in the data for the two treatments was observed for all four participants, phase two was implemented). In this phase, participants received the treatment that had been shown to be effective in phase one. Overall, data (Figures 8.7 and Phase 1 100 75 Phase 2 Self-Set Goals 50 Self-Set Goals Per Cent On Task 25 Subject 1 Coach-Set Goals 0 100 75 Self-Set Goals 50 Self-Set Goals 25 0 Figure 8.7â ‡ Coach-Set Goals 0 5 10 Sessions Subject 2 15 20 Per cent on task of participants with an internal locus of control. Adapted from S. M. Lambert, D. W. Moore and R. S. Dixon (1999) Gymnasts in training: The differential effects of self- and coach-set goals as a function of locus of control. Journal of Applied Sport Psychology, 11, 72–82 (Taylor & Francis Ltd, http://www.informaworld.com) by permission of the publisher. The alternating-treatments design in sport and exerciseâ … 137 Phase 1 100 Phase 2 75 Coach-Set Goals 50 Coach-Set Goals Per Cent On Task 25 Subject 3 Self-Set Goals 0 100 Coach-Set Goals 75 50 Coach-Set Goals 25 Self-Set Goals 0 Figure 8.8â ‡ 0 5 Subject 4 10 Sessions 15 20 Per cent on task of participants with an external locus of control. Adapted from S. M. Lambert, D. W. Moore and R. S. Dixon (1999) Gymnasts in training: The differential effects of self- and coach-set goals as a function of locus of control. Journal of Applied Sport Psychology, 11, 72–82 (Taylor & Francis Ltd, http://www.informaworld.com) by permission of the publisher. 8.8) revealed differential effects, with participants with a more internal locus of control spending more time on task under the self-set goals condition and those with an external locus of control spending more time on task under coach-set goals. Furthermore, in phase two of the study, when each participant was placed under optimal conditions for them as established in phase one (i.e., internals setting own goals and externals having coach set goals), all four stabilized their on-task behaviours over and above that displayed with the presentation of the alternative treatment. A final example of an ATD in a sport and exercise setting comes from Sariscsany, Darst and van der Mars (1995) who investigated the effects of three supervision patterns on students’ ‘on-task’ activities (i.e., participants engaging in teacher-directed activities) and practice skill behaviour (i.e., volleyball underarm and forearm pass). Three experienced PE instructors and three ‘off-task’ (i.e., inattentive) junior high school males served as participants. The ATD was used to assess on-task behaviour, total practice trials and appropriate practice trials under three supervision patterns. First, close supervision with feedback 138â … The alternating-treatments design in sport and exercise included a teacher positioned close to the targeted participant providing specific skill feedback for at least 50 per cent of the total practice time. Second, distant supervision with feedback consisted of a teacher being positioned away from the targeted behaviour and issuing specific skill feedback for at least 50 per cent of the practice time. Finally, distant supervision with no feedback entailed the teacher being located away from the target participant for 50 per cent of the practice time and issuing no specific skill feedback. Findings from the study indicated that when the treatments were successfully implemented the percentage of on-task behaviour was significantly higher during active supervision for two target participants (i.e., participants 1 and 2). In contrast, mixed results were demonstrated for total and appropriate practice trials across all three treatments for all participants. In summary, although the ATD is a flexible, adaptable and well-used design in mainstream applied behavioural research (Barlow et al. 2009), it has received little or no attention from researchers and practitioners in sport and exercise settings (Kinugasa et al. 2004). The challenge of embracing alternative methods such as the ATD to determine treatment or intervention effectiveness exists for those involved in sport and exercise. Finally, although the ATD is the most prevalent single-case method for comparing treatments, variations do exist that extend the flexibility and use of the design in applied behavioural research (Kazdin 1982). The following section introduces the main ATD design variations. Design variations The simultaneous-treatment design A variation to the ATD is the simultaneous-treatment design (STD; Browning 1967; Browning and Stover 1971). In the STD two or more treatments are presented simultaneously in a single case. Typically, the STD evaluates participants’ preference among a variety of treatments because they are available at the same time or in the same session. Indeed, the STD allows for the collection of information about treatment preferences (Kazdin 2003; Kazdin and Hartmann 1978; Kratochwill et al. 1984). The STD contrasts with the fast alternation of two or more treatments in the ATD and typically means that participants are not exposed to all treatments equally (Barlow and Hayes 1979). Although the STD has been popular in the single-case literature for a number of decades, only one example exists in applied research (Barlow et al. 2009). In this study Browning (1967) compared the effects of three procedures (praise and attention, verbal admonishment and ignoring) on reducing ‘bragging’ behaviour (i.e., the telling of untrue and grandiose stories) in a nine-year-old boy. Following a four-week baseline, the practitioners working with the boy (i.e., teams of two therapists) implemented the three procedures simultaneously. The three procedures were balanced across three groups of staff. After each week, the staff members The alternating-treatments design in sport and exerciseâ … 139 associated with a particular intervention were rotated so that all staff administered all of the interventions to the boy. A unique feature of this study’s design was the simultaneous availability of all treatment conditions to the boy. The specific consequence that the boy received for bragging depended on the staff members with whom the boy came into contact. Accordingly, the boy could choose the preferred schedule or treatment as treatments were simultaneously presented; thus he was not equally exposed to each treatment. In fact, the very structure of the STD ensures that the participant will not be equally exposed to all treatments because choice is forced (except in the unlikely event that both treatments are equally preferred; Barlow et al. 2009). The measure of treatment effectiveness was the frequency and duration of bragging incidents over time directed at the various staff members. Data from the participant, presented in Figure 8.9, indicated a preference for verbal admonishment, as indicated by the frequency and duration of bragging, and a lack of preference for ignoring. Therefore, ignoring became the treatment of choice and was continued by all staff. Despite its unpopularity in applied research, the STD is an important single-case design for understanding individual treatment preferences (Kazdin 2003). In certain applied settings (e.g., when exploring the effectiveness of new Mean No. Grandiose Bragging Responses 10 Total Frequency 9 × × (B) Positive attention (C) Verbal Admonishment (D) Purposely Ignore 8 7 6 5 4 3 × 2 0 × × 1 0 1 2 Uncontrolled Baseline 3 4 5 Controlled Baseline 6 7 B, C, D Treatments 8 9 10 D Treatment 11 Weeks Figure 8.9â ‡Total mean frequency of grandiose bragging responses throughout study and for each reinforcement contingency during experimental period. Adapted with permission from R. M. Browning (1967) A samesubject design for simultaneous comparison of three reinforcement contingencies. Behavior, Research, & Therapy, 5, 237–243. 140â … The alternating-treatments design in sport and exercise interventions) intervention preference may be an important component in understanding both treatment adherence and overall treatment effectiveness. Although exploring intervention preferences is an important facet of applied research, ‘preference’ is not the same as effectiveness (Barlow et al. 2009). For example, it is possible that participants may choose treatments that are the least invasive and time-consuming and thus possibly less effective in the long term. Despite this obvious limitation, it has been recommended that the STD needs to be implemented in areas of behaviour change where information on treatment preferences is desired (Barlow et al. 2009). Therefore, the STD may be relevant when using techniques that are shrouded in popular misconception or confusion (e.g., hypnosis). To this end, gathering information on why certain techniques were and were not preferred by participants has important implications for applied researchers and practitioners looking to develop and modify innovative modes of intervention (Grindstaff and Fisher 2006). For example, asking a client for feedback about hypnotic procedures allows a practitioner to make modifications to how they deliver the technique in the future. Gathering information on intervention preference is likely to lend itself more closely to qualitative methods (e.g., social validation data) rather than self-report measures. Overall, the STD is a variation of the ATD and typically evaluates participants’ preferences among a variety of treatments that are presented simultaneously. Although the STD has been presented as a design useful for determining intervention effectiveness (see Browning 1967; Kazdin 1982), some maintain that the STD is unsuitable for studying differential effects of treatments or conditions and is therefore not well suited to the evaluation of intervention effectiveness (Barlow et al. 2009). To fully understand the appropriateness of the STD in applied settings (e.g., sport and exercise contexts) further research is clearly needed. Randomization design The randomization design (Edgington 1966, 1972) in the context of ATDs refers to the presentation of alternative treatments in random order (Barlow et al. 2009; Kazdin 1982). For example, according to Kazdin (1982), baseline (A), treatment 1 (B) and treatment 2 (C) can be presented to participants on a daily basis in the order of A–B–C–B–A–C–A–C–B–C–A–B–C–B–A–B–C–A. Therefore, each day a different condition is presented, on the proviso that each condition is presented an equal number of times. In the intervention phase of an ATD, the alternative interventions must be balanced across stimulus conditions (e.g., time or setting). Therefore, randomly ordering the sequence in which treatments are applied provides researchers with a strategy to organize the presentation of treatments. To illustrate, an exercise psychologist may administer imagery and self-talk on alternative days over a three-week period to evaluate their effects on a client’s exercise efficacy. Because the conditions and/or treatments administered on a given day are randomly determined, data are suggested The alternating-treatments design in sport and exerciseâ … 141 to be more amenable to statistical analysis as a means of determining intervention effectiveness (Edgington 1966, 1972). In summary, the main design variations related to the ATD are the STD and the randomization design. Although both of these variations have received little application in the applied behavioural literature they are important additions for researchers and practitioners looking for methods to help them derive effective interventions. Problems and limitations of the alternating-treatments design As noted previously, the ATD is a flexible and adaptable design but it carries one major limitation: multi-treatment interference (MTI; Campbell and Stanley 1963). In essence, because single-case designs typically involve the repeated measurement of variables from the same participant, data can be serially dependent (i.e., data collected at specific moments in time can be influenced by previous measures; see Ottenbacher 1986). This can also occur with data collected under different phases or conditions (Barlow and Hayes 1979). For example, in the ATD, two or more interventions are alternated rapidly over time, making it likely that the effects from one treatment may carry over and influence the following intervention. Therefore, MTI refers to the effect that one treatment has on another; when a participant is exposed to two or more treatments, the experience with one treatment may influence the effectiveness of others (Wolery, Bailey and Sugai 1988). Moreover, MTI is likely to be prevalent in all conditions, including baselines and participants’ non-experimental experiences (e.g., participant history; Birnbrauer 1981). When treatments are compared within subjects, four outcomes are possible (Barlow and Hayes 1979): (1) treatments are made more effective because of the exposure to other treatment(s), (2) treatments are made less effective because of the exposure to other treatment(s), (3) one treatment is made more effective because of the exposure to a first and (4) none of the treatments influences each other. Indeed, the first three potential outcomes lend themselves to the possibility of drawing incorrect or misleading conclusions about intervention effectiveness. Therefore, researchers and practitioners are encouraged to control, detect and describe the presence of MTI within their studies (Barlow et al. 2009; Holcombe et al. 1994). Problems in drawing conclusions about intervention effectiveness also exist in the multimodal intervention designs seen in the sport and exercise literature (e.g., Barker and Jones 2006; Collins et al. 1999; Freeman et al. 2009; Hanton and Jones 1999; Thelwell and Greenlees 2001). These designs make it difficult to determine which aspect of an intervention has had the greatest effect on target variables. Continuing with the theme of MTI this section next explores some related concerns (i.e., sequential confounding, carry-over effects and alternation effects; Barlow and Hayes 1979; Kazdin 2003; Ulman and Sulzer-Azaroff 1975) and also explains how MTI can be minimized. First, sequence effects (also known as 142â … The alternating-treatments design in sport and exercise sequential confounding or order effects) refer to situations in which the order of treatment use influences the potency of one or more of the treatments (Barlow and Hayes 1979). Sequence effects are posited to be particularly acute in singlecase designs in which experimental conditions are compared within rather than across participants, because in nearly all cases participants must experience one treatment before the other; once that experience has occurred it cannot be taken away (Holcombe et al. 1994). For example, a researcher interested in alternating the interventions of pre-performance routines and superstitious behaviours on basketball free-throw shooting may find it difficult to prevent participants from using elements of the pre-performance routine in future shooting conditions. Controlling for sequence effects in ATDs is therefore attempted by rapidly alternating treatment implementation. Using interventions for a brief time is less likely to produce a learning history that could bring about sequence effects (Holcombe et al. 1994). Another recommendation for dealing with sequence effects is to arrange for a random sequencing of treatments within the intervention phase (Barlow et al. 2009). ‘Carry-over’ effects are influences of one treatment on another that arise from the characteristics of the treatments rather than the order in which they are administered (Holcombe et al. 1994). Carry-over has been suggested to have both positive and negative effects (Barlow and Hayes 1979). Positive carry-over effects would be demonstrated if treatment B were more effective when it was alternated with treatment A than if it were the only treatment administered. For example, if a participant is exposed to a relaxation strategy that is alternated with hypnosis it is likely that exposure to relaxation will facilitate the potency of hypnosis given that relaxation is a key aspect common to most hypnotic procedures (Barker and Jones 2006). In contrast, negative carry-over would be revealed if treatment B were less effective when it was alternated with treatment A than if it were administered alone. For example, the effectiveness of positive self-talk is likely to be less effective if alternated with thought stopping. Accordingly, from these examples one would make the assumption that treatment A is somehow interfering with the effects that one would see from treatment B if it were delivered alone (Barlow et al. 2009). Because of the potential for sequence effects in ATDs a number of recommendations have been made to limit these effects (Barlow et al. 2009): counterbalancing the order of the treatments, separating treatment sessions with a time interval (e.g., one session per week) and providing slower and discriminable treatment alterations (e.g., Powell and Hake 1971) may all reduce carry-over effects. This section has identified the major limitations of the ATD – MTI and its associated concerns. Although these limitations of the ATD can be alleviated through the use of the recommendations outlined above, sometimes it may be desirable to assess directly the extent to which MTI and more specifically carryover effects exist in a study (e.g., McGonigle et al. 1987; Shapiro, Kazdin and McGonigle 1982). Readers are directed to the work of Sidman (1960) for a more detailed account of the procedures involved in assessing MTI. The alternating-treatments design in sport and exerciseâ … 143 Evaluation of the design The ATD has a number of advantages over the reversal and multiple-baseline designs that make it applicable for applied behavioural research (see Barlow et al. 2009; Kazdin 1982). In particular, these advantages make the ATD appropriate for sport and exercise researchers and practitioners (Bryan 1987; Hrycaiko and Martin 1996; Kinugasa et al. 2004). The ATD allows comparison of various treatments and their effects over time, therefore facilitating the literature base on evidence-based practice. Second, it is possible to detect delayed treatment effects because the ATD can involve ongoing baseline as a condition for comparison. Third, the ongoing baseline allows the ATD to be used with variables pertinent to sport and exercise settings (e.g., sport performance, exercise adherence) that occur at unstable rates (McKenzie and Liskevych 1983). Fourth, the concurrent use of treatments in the ATD means that a baseline may not be a requirement or if one is it does not have to be a lengthy baseline, which can be both practically and ethically beneficial (Zhan and Ottenbacher 2001). This is possible because treatments are alternated after short periods of time. Fifth, because of concurrent measurement of treatments, less effective treatments can be detected and terminated easily and without delay (McKenzie and Liskevych 1983). Sixth, the ATD is pertinent to sport and exercise settings because it uses brief samplings of variables rather than lengthy phases as outlined in other single-case designs (e.g., A–B design) and is therefore less intrusive to the training and competition schedules of exercisers and athletes. Finally, the ATD does not involve practitioners having to deal with the ethical dilemma of withdrawing a treatment (e.g., Pates et al. 2001). Overall, the ATD is a strong, flexible and clinically useful strategy for researchers and practitioners engaging in single-case experiments (Barlow et al. 2009). Summary The ATD is particularly useful when one wishes to compare two or more potentially effective treatments with each other for the same participant(s). By rapidly alternating treatments it is possible to allow for multiple comparisons of the target variables under each treatment. The major variation to ATD is the STD in which two or more treatments are presented simultaneously, providing information regarding treatment preference of participants. Causal inferences about intervention effectiveness can be difficult in the ATD and STD because of the prevalence of MTI although this apparent threat to internal validity can be reduced by counterbalancing across participants or through the randomization of treatment conditions (Barlow et al. 2009). Overall, the ATD carries many advantages over and above other single-case designs, which make it an attractive approach for applied practitioners and researchers engaged in comparing effective treatments. Finally, the ATD has received a lack of application in sport and exercise in comparison with mainstream applied research. 144â … The alternating-treatments design in sport and exercise The previous four chapters have outlined the major tenets of the main design variations (i.e., withdrawal, multiple-baseline, changing-criterion and alternating-treatments designs) pertinent to single-case research methods. Throughout these chapters observations have been made regarding analytical procedures used to determine change or intervention effectiveness. The following chapter provides a more thorough insight into the data analysis procedures involved with single-case data. Key points The alternating-treatments design is a single-case design in which two or more interventions are alternated rapidly in order to compare intervention effectiveness. The simultaneous-treatments design is a design variation in which two or more treatments are presented simultaneously in a single case. This design is used to evaluate participants’ preference among a variety of treatments. Serial dependence is when data are influenced by earlier measures. Multi-treatment interference is a threat to the internal validity of an ATD in which the effects of one intervention or treatment interact with other (future) interventions or treatments. Sequence effects refers to situations in which the order of treatment or intervention use influences the potency of one or more treatments. Carry-over effects are influences of one treatment on another that arise from the characteristics of the treatments rather than the order in which they are administered. Counterbalancing is a methodological procedure in an ATD in which the order of treatments is varied (counterbalanced) to eliminate order effects. Randomization is a methodological procedure in which the alternating of treatments is not predictable but occurs randomly during the intervention phases. Guided study Based upon your reading of Chapter 8 please take some time to respond to the following review questions: How does the alternating-treatments design differ from the changingcriterion, withdrawal and multiple-baseline designs? Discuss the major tenets of the alternating-treatments design. Discuss the major tenets of the simultaneous-treatments design. Explain the limitations of the alternating-treatments design. Discuss multi-treatment interference and outline (with examples) how its effects can be minimized in the alternating-treatments design.