Introduction to Experimental Psychology PDF

INTRODUCTION TO EXPERIMENTAL PSYCHOLOGY Tooba Arshad Institute of Professional Psychology, Bahria University- Karachi Campus Definition Experimental Psychology is the study of psychological issues that uses experimental procedures The branch of psychology dealing with the study of em...

INTRODUCTION TO EXPERIMENTAL PSYCHOLOGY Tooba Arshad Institute of Professional Psychology, Bahria University- Karachi Campus Definition Experimental Psychology is the study of psychological issues that uses experimental procedures The branch of psychology dealing with the study of emotional and mental activity, as learning, in humans and other animals by means of experimental methods Discover the process underlying the behavior and cognition Conducts research with the help of experimental methods What is the difference b/w research and experiment? What is Experimental Psychology? The phrase “experimental psychology” refers to A specific methodological approach to the study of psychology As well as to several specific areas of research within psychology which predominantly use experimental methods Who is an Experimental Psychologist? A psychological scientist who: Primarily uses the experimental method to study behavior Answers questions about the when, where, and why of behavior by careful manipulation and control of relevant variables Carefully records and conducts quantitative analysis of the behavioral data Insists on the cautious and parsimonious interpretation of those empirical data in the light of both familiar and innovative theoretical interpretations Nature Methodological approach rather than a subject and encompass varied fields within psychology To explore any area of psychology that can be studied through experiments Experimental psychology involves the collection of reliable and quantifiable behavioral data Often empirical tests are conducted under controlled conditions in order to study a particular psychological phenomenon or to test hypotheses concerning that phenomenon Scope Neuroscience Memory Developmental Thinking psychology Language Sensation Motivation Perception Emotion Attention Social psychology Consciousness Learning Example Interpersonal relations between people of different statuses The eye movements of new born children Personality traits The etiology of schizophrenia Brain patterns of people solving problems Attractiveness of average faces These topics can be studied through personal experience and subjective arguments - nonscientific and unreliable Subjective analysis needs prescribed method for valid and reliable conclusion Experiments Aristotle’s method of rational logic versus Galileo’s method of experimentation Acceleration of falling objects Aristotle “common sense logic” Galileo's experiment Statement of hypothesis Observation Replicability Development of law Control problems Definition of Experiment Experiment is an observation of behavior under controlled conditions The word “experiment” is derived from the Latin word experimentum, means ‘a trail’ or ‘test’ Eysenck (1996) “ An experiment is the planned manipulation of variables in which at least one of the variables that is the Independent Variable (IV) is altered under the predetermined conditions during the experiment.”  Jahoda “Experiment is the method of testing hypothesis” Festinger and Katz “ The essence of experiment may be described as observing the effect of DV after the manipulation of IV” It is the arrangement of conditions or procedures for testing and hypothesis Control IV to establish cause and effect r/s  Psychological Experiments Refers to investigations in which at least one variable is manipulated in order to study cause-and-effect r/s Includes manipulations of some variables, control and ascertains of effects on another variables Like Galileo psychologist also work on the lawful assumptions of nature Only the subject matter and technical equipment is different  Psychologist study thoughts and behaviors The subject matter and scientific tools separate the disciplines while experimentation unites the scientists Center of experimental methods in psychology Control of extraneous variables Minimizing the potential for experimenter bias Counterbalancing the order of experimental tasks Adequate sample size The use of operational definitions (reliable and valid) Aims of Experimental Psychology Study human behavior in a different context Description of behavior using careful observations Explanation identifying the cause(s) of behavior Prediction allows for specification of the conditions under which a behavior will or will not occur  George C. Homans (1967) “what makes science (is) its aims, not its results: if it aims at establishing more or less general relationships b/w properties of nature, when the test of the truth of a relationship lies finally in the data themselves, then the subject is science” Scientific inquiry of psychology: reveal the underlying reality to behavior and thoughts through scientific analysis Basic assumption: human is basically a system that may be understood through scientific experimentation and rational analysis Types of Research Basic Research Applied Research Establishes a reservoir of Established concepts are data, theoretical further researched and explanations, and applied concepts Concept application Concept development Basic aim at solving No immediate practical specific problems goals E.g. How to cure E.g : what is bedwetting? bedwetting  Basic Research the process of collecting and analyzing information to develop or enhance a theory Comes from observation Applied Research conducted for the purpose of applying or testing theory and evaluating its usefulness for solving problems Comes from prior theories and researches You cannot confirm a theory-you can support it Scientific Context of Experiments Three basic techniques Experimental Psychologists uses three basic techniques: Introduce an element in a controlled environment and measures its effect on thought or action Select a group that has certain well-defined characteristics and measure the psychological characteristics of that group, usually contrasting those characteristics with a control group Observe behavior in a naturalistic environments and make empirical measurement of psychological characteristics Spallanzani’s Experiment Basic Steps in Experimental Process Hypothesis Design Experiment Perform Experiment Make Observations Conclusion Hypothesis Is a tentative statement that is being checked It tells the relationship which researcher expects to find b/w IV and DV Halpern (1989) “ A hypothesis is a tentative set of beliefs about the nature of the world, a statement about what you expect to happen if certain conditions are true.” Effect of IV on DV, r/s b/w IV and DV E.g. Music will increase the learning of students One tail/ Directional hypothesis Two tail/ non-directional hypothesis Example???? Operational Definition It is the statement of operations necessary to produce and measure a concepts a description of something in terms of the operations (procedures, actions, or processes) by which it could be observed and measured It defines the concepts in terms of how it is measured Necessary to do a creditable research as they: Communicates effectively Replicate Retains full meaning of the concept even though variability is there  Easy to define concrete concepts like time Abstract concepts: difficult to define empirically; anxiety, intelligence, hostility etc. Psychological concepts are tied to the objective circumstances Uses scales or tests Suited for the specific research question Example?????? Effect of modality of teaching on learning of students On campus Modality Online Hypothesis Students will learn better in on campus classes as compare to online classes The modality teaching will effect the learning of students / the learning of students will differ in online vs on campus classes Learning It is the understanding of the concept (Conceptual) which will be measured through a test. The higher the score is the better the learning is (Operational). Modality The modality is defined as the contact with the students …. When students have in person contact with the teacher its called on campus and when they will be virtually contacted it will be called online. Effect of Social Media (IV) on Emotional Intelligence (DV) of Adolescents (Population) Hypothesis? Operational definitions? Eg Hypothesis: Use of SM will effect the EI of adolescents Use of SM will negatively effect EI of … The more the use of SM the less the EI of ….. Operational definitions: Social Media: The total of hours mentioned by the phone (App XYZ). The usage more 3 hours is excessive use of SM while 1 hour is moderate use of SM EI: recognition and utilization of emotions which will be measured through Maleeha EI test. The higher the score is the more EI is. Adolescents Adolescents are the individuals who lives in the age range of 13-18 Variables D’ Amato (2004) “Any measurable attributes of those attributes, qualities and characteristics of objects, events, things or beings” Characteristics or conditions that are manipulated, controlled or observed by the experimenter In a scientific investigation- any condition that may change in quantity or quality Intelligence, anxiety, aptitude, income, education, authoritarianism, achievement Independent & Dependent Variables In an experiment one variable is manipulated and its effect on the other variable is observed The manipulated variable is Independent Variable (IV) The variable whose reaction is being observed in called Dependent Variable (DV) Psychologist see the effect of one variable on other Cause-and-effect relationship  Experimental, controlled, or treatment variables It is the if part of the “If------- then --------” statement of the hypothesis The variable on the basis of which predictions are made  Theory of control Precise effect of one variable on other By holding some variable constant or manipulating Simple Experiment Stage 1 Stage 2 Semen + Sperm Semen – Sperm (Control Condition) (Experimental Condition)  Simple Experiment: one IV and one DV DV mostly answers the research questions of the experimenters’ questions Dependent Responses: Interest of Psychologists Types of IVs First: experimenters systematically manipulates the variable (the amount of Reward; Type- E) Second: selection of the subjects on the basis of certain characteristics of interest (I.Q, Age; Type-S) Experimenter- manipulated IV Lorge (1930) Massed vs distributed practice Tracing stars (20 trails) 3 groups (no interval, interval of an hour, interval of 24 hrs) The shorter the time interval the better the results No interval, interval of an hour, interval of 24 hrs are controlled IVs The time to trace the stars in the DV Constant factors: same task and number of trials  IV DV??? Hypothesis??? Operational Definition???  Example from Social Psychology Asch (1952) Law of Primacy 2 groups List of adjectives Intelligent, industrious, impulsive, critical, stubborn, envious Primacy information The order of adjectives is IV Impression of the person is DV Experimenter-selected IV Some characteristics that cannot be controlled or manipulated Selection of subjects on the basis of the presence or absence of those characteristics IQ, authoritarianism, gender, race, presence of male hormones, personality types, diagnostic classification, age, social status Example: Impact of authoritarianism on learning  Bebow and Stanely (1980) differentiate between mathematical skills of boys and girls 9,927 students performed mathematical portion of SAT Boys scored significantly higher EP is the study of manipulated IVs but in some cases we have to select the IVs Classification of IVs Underwood (1906) classified IV’s on the basis of manipulation Task Variables Environmental Variables Subject Variables Depends on the operational definition Example???? DV Any measured behavioral variable of interest to the experimenter in a psychological investigation is DV Change in DV depends upon the change in IV Underwood described it as response variable In “If---------then-------” statement it is the then part of the hypothesis Change in IV can cause change in DV but not vice versa Experimental & Control Groups The Experimental Group: receives the experimental treatment- manipulation by the experimenter Control Group: treated like the experimental group but did not receive the treatment Different levels on IV on the basis of the treatment Spallanzani Experiment: Sperm-free filters were experimental group  Supa, Cotzin and Dallenbach (1944) blind people Exp Group 1: No Facial vision (wore veils and gloves) Exp Group 2: No auditory cues (wore ear plugs) Control Group Obstacles: screens Why do we need a control group?? Placebo control group?? Paul (1966) treating speech phobia 4 groups from public speaking class Exp Group 1: Behavior therapy (100%) Exp Group 2: Insight therapy (60%) Exp Group 3: placebo pills (73%) Group 4: control group (32%) Ensures that it is the effect of IV not other variables Control group controls the experimenters bias Also provides the baselines Blind The term blindness reference to the hiding of the treatment process that has been introduced in the exp groups from the participants Single blind (nest building) Double blind (Paul’s experiment) Extraneous Variables Which are more or less similar to IV or variables that have the capacity to influence the DV Control means the exercise of the scientific method whereby the various treatments in an exp are regulated so that casual factors may be unambiguously identified Best research design- full control of extraneous variables Confounding Variables Variables other than the IV that is not equivalent in all conditions Mistakenly manipulated along with the IV Lead towards wrong conclusion Random assignment can reduce that Random: not a thing, but to the lack of thing, lack of pattern, structure or regularity Difference between Extraneous and Confounding An extraneous variable is a variable that MAY interfere with the independent variable in explaining the outcome of a study. A confounding variable is a variable that DOES cause a problem because it is empirically related to both the independent and dependent variable. Methods to Control Randomization: technique in which each member of the population or universe at large has an equal and independent chance of being selected in the groups Phases of Randomization Random selection of subjects Random assignment of subjects Random assignment of treatment Helps to reduce the effect of extraneous variables Basically it distributes the extraneous effect equally in each group Large sample Experimental Design The design of controlled conditions under which one might make empirical observations of actions, thoughts, or behavior of humans or animals within the context of testable hypothesis, that leads towards anticipated r/s b/w the conditions of an experiment and its outcome Strategies Laboratory Experiments Field Experiments Laboratory Experiments A further difficulty with the experimental method is demand characteristics. Demand characteristics are all the cues which convey to the participant the purpose of the experiment. If a participant knows they are in an experiment they may seek cues about how they think they are expected to behave. Another problem with the experimental method concerns ethics. For example, experiments often involve deceiving participants to some extent. However, it is possible to obtain a level of informed consent from participants. Field Experiments Experiment that is conducted in a “real world” situation. Participants are not usually aware that that they are participating in an experiment. The IV is still manipulated unlike in natural experiments. High in ecological validity and may avoid demand characteristics as the participants are unaware of the experiment. Harder to control confounding variables Time consuming and expensive to conduct. Not usually possible to gain informed consent from the participants and it is difficult to debrief the participants. Types of Experimental Designs Single-group or Within-subjects Experimental Designs Subjects plays the role of the control as well Goes through all conditions /levels of IVs Separate Group or Between Subjects Experimental Designs Being used to measure several IVs Different groups are made on the basis of their characteristics or randomly assigned Each subject or group goes under one condition only Trial Position Effect under Massed & Distributed Practice The spacing effect is the phenomenon whereby animals (including humans) more easily remember or learn items when they are studied a few times spaced/distributed over a long time span ("spaced/distributed presentation") rather than repeatedly studied in a short span of time (" massed presentation"). The phenomenon was first identified by Hermann Ebbinghaus. Practically, this effect suggests that "cramming" (intense, last-minute studying) the night before an exam is not likely to be as effective as studying at intervals in a longer time frame. Important to note, however, is that the benefit of spaced presentations does not appear at short retention intervals, in which massed presentations tend to lead to better memory performance.  Lee & Genvose have found out the influence of distribution of practice conditions (through analysis of empirical studies) on learning and performance of motor skills. Distributed practice enhances performance Effects of distributed practice are larger on the performance than the first trail It results in greater learning 090078601