2-THEORY-AND-RESEARCH.pdf

T H E O RY A ND RE S E A RC H CHAPTER 2 Pre p are d by: MAILLEN GRACE G. QUILALA Instructor  B A S I C T H E O RE T I C A L I S S U E S Theory – set of concepts and propositio...

T H E O RY A ND RE S E A RC H CHAPTER 2 Pre p are d by: MAILLEN GRACE G. QUILALA Instructor  B A S I C T H E O RE T I C A L I S S U E S Theory – set of concepts and propositions designed to organize, describe, and explain an existing set of observations. A parsimonious theory is one that uses relatively few explanatory principles to explain a broad set of observations. A theory is falsifiable when it is capable of generating predictions that could be disconfirmed. A heuristic theory is one that continues to stimulate new research and new discoveries. Hypotheses – possible explanations for phenomena, used to predict the outcome of research. ISSUE 1: NATURE VERSUS NURTURE At present, most developmental psychologists do not believe that development is primarily due to either nature (determined by biology) or nurture (determined by experience). Instead, there is a clear understanding that development is due to both nature and nurture. ISSUE 2: ACTIVE VERSUS PASSIVE Some theories portray children, including infants, as continually active in their own development, as they decide what they will attend to and process, seeking out things that are particularly interesting to them. While some children are depicted as more passive, learning from stimulation that is presented to them.  ISSUE 3: CONTINUITY VERSUS DISCONTINUITY In the issue of continuity, human development is viewed as an additive process that occurs gradually and continuously, without sudden changes. While in the issue of discontinuity, the road to maturity is described as a series of abrupt changes, each of which elevates the child to a new and presumably more advanced level of functioning. ISSUE 4: STABILITY VERSUS CHANGE Developmentalists who emphasize stability in development argue that stability is the result of heredity and possibly early experiences in life. While those who emphasize change take the more optimistic view that later experiences can produce change. T H E O RE T I C A L P E RS P E C T I V E S PERSPECTIVE IMPORTANT THEORIES BASIC PROPOSITIONS Psycho-analytic Freud’s psychosexual theory Behavior is controlled by powerful unconscious urges. Erikson’s psychosocial theory Personality is influenced by society and develops through a series of crises. Learning Behaviorism, or traditional learning theory People are responders; the environment controls behavior. (Pavlov, Skinner, Watson) Children learn in a social context by observing and imitating Social learning (social cognitive theory (Bandura) models; they are active learners Cognitive Piaget’s cognitive-stage theory Qualitative changes in thought occur with development. Children are active initiators of development. Vygotsky’s sociocultural theory Social interaction is central to cognitive development. Information-processing theory Human beings are processors of symbols. Contextual Bronfenbrenner’s bioecological theory Development occurs through interaction between a developing person and five surrounding, interlocking contextual systems of influences. Evolutionary/ Evolutionary psychology; Human beings are the product of adaptive processes, which Biological Bowlby’s attachment theory interact with the current environment to shape behavior..  PERSPECTIVE 1: PSYCHOANALYTIC Sigmund Freud (1856-1939) was a Viennese physician who had profound effect on the field of psychology. He was the originator of psychoanalytic perspective---view of human development as shaped by unconscious forces that motivate human behavior. He relied heavily on such methods as hypnosis, free association, and dream analysis, because they gave some indication of unconscious motives that patients had repressed.  He proposed that humans were born with a series of innate, biologically based drives such as hunger, sex, and aggression. He thought people were motivated to satisfy their urges, and that much of development involved learning how to do so in socially acceptable ways. He believed that early experiences shaped later functioning, and he drew attention to childhood as an important precursor to adult behavior. He promoted the idea that there was a vast, hidden reserve to our psyche, and what we consciously know about and experience is only the small tip of an iceberg of who we are. FREUD’S PSYCHOSEXUAL DEVELOPMENT Freud believed people are born with biological drives that must be redirected to make it possible to live in society. He proposed three hypothetical parts of the personality: the id, the ego, and the superego. His psychosexual theory proposes that the id, the ego, and the superego, develop and gradually become integrated in a series of five developmental psychosexual stage.  Id present at birth operates under the pleasure principle---the drive to seek immediate satisfaction of their needs and desires When gratification is delayed, as it is when infants have to wait to be fed, they begin to see themselves as separate from the outside world Ego develops gradually during the first year or so of life and operates during the reality principle its aim is to find realistic ways to gratify the id that are acceptable to the superego Superego develops at about age 5 or 6 it includes the conscience and incorporates socially approved “should” and “should nots” into the child’s value system highly demanding; if its standards are not met, a child may feel guilty or anxious  Freud thought that sex was the most important instinct because he discovered that his patients’ mental disturbances often revolved around childhood sexual conflicts they had repressed. As stated by Freud, a person goes through a sequence of five stages and along the way there are needs to be met. He identified specific erogenous zones or “pleasure areas” for each stage of development. A fixation occurs if needs are not met along the area. 1. Oral stage (birth to 1 year) – the sex instinct centers on the mouth because infants derive pleasure from such oral activities as sucking, chewing, and biting. Feeding activities are particularly important. 2. Anal stage (1 to 3 years) – voluntary urination and defecation become the primary methods of gratifying the sex instincts. Toilet- training produces major conflicts between children and parents. The emotional climate that parents create can have lasting effects. 3. Phallic stage (3 to 6 years) – pleasure is now derived from genital stimulation. Children develop an incestuous desire for the opposite- sex parent (called the Oedipus complex for boys and Electra complex for girls). Anxiety stemming from this conflict causes children to internalize the sex-role characteristics and moral standards of their same-sex parental rival. 4. Latency stage (6 to 11 years) – traumas of the phallic stage cause sexual conflicts to be repressed and sexual urges to be rechanneled into schoolwork and vigorous play. The ego and superego continue to develop as the child gains more problem-solving abilities at school and internalizes societal values. 5. Genital stage (age 12 onward) – puberty triggers a reawakening of sexual urges. Adolescents must now learn how to express these urges in socially acceptable ways. If development has been healthy, the mature sex instinct is satisfied by marriage and raising children. PERSPECTIVE 1: PSYCHOANALYTIC Erik Erikson (1902-1994) was one of the pupils of Freud who modified and extended Freudian theory by emphasizing the influence of society on the developing personality. He was a pioneer in taking a life- span perspective. In his psychosocial development, the socially and culturally influenced process of development of the ego, or self.  Epigenetic principle states that “anything that grows has a ground plan, and out of this ground plan the parts arise, each having its time of special ascendancy, until all parts have arisen to form a functioning whole.” – Erik Erikson (1980) Erikson believed that people face eight major crises, which he labeled psychosocial stages, during the course of their lives. Each crisis emerges at a distinct time dictated by biological maturation and the social demands that developing people experience at particular points in life. Each crisis must be resolved successfully to prepare for a satisfactory resolution of the next life crisis. If a stage is managed well, we carry away a certain virtue or psychosocial strength which will help us through the rest of the stages of our lives. 1. Basic trust versus Mistrust (birth to 1 year) Infants must learn to trust others to care for their basic needs. If caregivers are rejecting or inconsistent, the infant may view the world as a dangerous place filled with untrustworthy or unreliable people. The primary caregiver is the key social agent. Virtue: Hope 2. Autonomy versus Shame and Doubt (1 to 3 years) Children must learn to be “autonomous”---feed and dress themselves, look after their own hygiene, etc. Failure to achieve this independence may force the child to doubt his or her own abilities and feel ashamed. Parents are the key social agents. Virtue: Will 3. Initiative versus Guilt (3 to 6 years) Children attempt to act grown up and will try to accept responsibilities that are beyond their capacity to handle. They sometimes undertake goals or activities that conflict with those of parents and other family members, and these conflicts may make them feel guilty. Successful resolution of this crisis requires a balance: The child must retain a sense of initiative and yet learn not to impinge on the rights, privileges, or goals of others. The family is the key social agent. Virtue: Purpose 4. Industry versus Inferiority (6 to 12 years) Children must master important social and academic skills. This is a period when the child compares himself or herself with peers. If sufficient industrious, children acquire the social and academic skills to feel self-assured. Failure to acquire these important attributes leads to feelings of inferiority. Significant social agents are teachers and peers Virtue: Skill 5. Identity versus Role Confusion (12 to 20 years) This is the crossroad between childhood and maturity. The adolescent grapples with the question “Who am I?” Adolescents must establish basic social and occupational identities, or they will remain confused about the roles they should play as adults. The key social agent is the society of peers. Virtue: Fidelity 6. Intimacy versus Isolation (20 to 40 years) The primary task at this stage is to form strong friendships and to achieve a sense of love and companionship with another person. Feelings of loneliness or isolation are likely to result from an inability to form friendships or an intimate relationship. Key social agents are lovers, spouses, and close friends (of both sexes). Virtue: Love 7. Generativity versus Stagnation (40 to 65 years) At this stage adults face the tasks of becoming productive in their work and raising their families or otherwise looking after the needs of young people. These standards of “generativity” are defined by one’s culture. Those who are unable to or unwilling to assume these responsibilities become stagnant and self centered. Significant social agents are the spouse, children, and cultural norms. Virtue: Care 8. Ego Integrity versus Despair (old age) The older adult looks back in life, viewing it as either a meaningful, productive, and happy experience or a major disappointment full of unfulfilled promise and unrealized goals. One’s life experiences, particularly social experiences, determine the outcome of this final life crisis. Virtue: Wisdom  PERSPECTIVE 2: LEARNING Theorists within the learning perspective argues that development was the result of learning, a relatively long-lasting change based on experience or adaptation to the environment. Learning theorists were not interested in the inner working of the mind because those processes could not be directly observed. Rather, behavior is the focus as it is observable and countable and confers great objectivity. Psychologists at the time also viewed the mind as tabula rasa, a blank slate upon which experience could write. In this view, everything a person became depended upon experience. Behaviorists saw development as continuous, emphasizing incremental quantitative change over time, and reactive, occurring in response to environmental input.  BEHAVIORISM Behaviorism is a learning theory that emphasizes the predictable role of environment in causing observable behavior. Behaviorists hold that human beings at all ages learn about the world the same way other organisms do: by reacting to conditions or aspects of their environment that they find pleasing, painful, or threatening. Behavioral research focuses on associative learning, in which a mental link is formed between two events.  CLASSICAL CONDITIONING Ivan Pavlov (1849-1936) was a Russian physiologist who devised experiments in which dogs learned to salivate at the sound of a bell that rang at feeding time. These experiments were the foundation for classical conditioning, in which a response (salivation) to a stimulus (the bell) is evoked after repeated association with a stimulus that normally elicits the response (food). CLASSICAL CONDITIONING John B. Watson (1878-1958) applied such stimulus- response theories to children, claiming the he could mold any infant in any way he chose. He was a strong proponent of the importance of learning in human development and the father of a school of thought known as behaviorism (Horowitz, 1992). In one of the earliest and most famous demonstrations of classical conditioning in human beings, he taught an 11-month old baby known as “ Little Albert” to fear furry white objects.  In this study, Albert was exposed to a loud noise when he started to stroke a rat. The noise, Albert whimpered with fear when he saw the rat. Albert also started showing fear responses to white rabbits and cats, and the beards of elderly men. The study, although unethical, demonstrated that fear could be conditioned. OPERANT CONDITIONING B.F. Skinner (1904-1990) was an American psychologist who argued an organism--- animal or human---will tend to repeat a response that has been reinforced by desirable consequences and will suppress a response that has been punished. Operant conditioning is a learning based on association of behavior with its consequences. An individual learns from the consequences of “operating” on the environment.  Reinforcement – the process by which a behavior is strengthened, increasing the likelihood that the behavior will be repeated. o Positive reinforcement – when a desirable stimulus is added to increase behavioral response. o Negative reinforcement – when an undesirable stimulus is removed to increase behavioral response. Punishment – the process by which a behavior is weakened, decreasing the likelihood of repetition. o Positive punishment – when a stimulus is added to decrease behavioral response. o Negative punishment – when you removed a pleasant stimulus to decrease behavioral response. Examples: 1. Gabriel and his friends were assigned to do community service because they were caught by their teacher cheating during the examination. 2. Mara does the household chores in order for her mother to stop nagging her. 3. Julienne’s father gives him P100 for every perfect score that he gets. 4. Eleanor’s parents confiscated her phone for one week because she went home late last night.  SOCIAL LEARNING (SOCIAL COGNITIVE) THEORY Albert Bandura (1925-2021) was an American psychologist who developed many of the principles of social learning theory---theory that behaviors are learned by observing and imitating models. He agreed with Skinner that operant conditioning is an important type of learning , particularly for animals. However, he argues that people are cognitive beings--- active information processors---who, unlike animals, think about the relationships between their behavior and its consequences.  Reciprocal determinism – the notion that the flow of influence between children and their environments is a two-way street; the environment may affect the child, but the child’s behavior also influences the environment. Observational learning (modeling) – learning through watching the behavior of others. This learning could not occur unless cognitive processes were at work. We must attend carefully to a model’s behavior, actively digest, or encode, what we observe, then store this information in memory in order to imitate what we have observed. Self-efficacy – sense of one’s capability to master challenges and achieve goals.  PERSPECTIVE 3: COGNITIVE The cognitive perspective focuses on thought processes and the behavior that reflects those processes. It views that thought processes are central to development. It includes that cognitive-stage theory of Piaget, Vygotsky’s sociocultural theory of cognitive development, and the information- processing approach.  JEAN PIAGET’S COGNITIVE-STAGE THEORY Jean Piaget (1896-1980) was a Swiss theoretician who began to study intellectual development during the 1920s. Through his careful observations and thoughtful questions, Piaget developed the cognitive-stage theory---theory that children’s cognitive development advances in a series of four stages involving qualitatively distinct types of mental operations.  Piaget suggested that that cognitive development begins with an inborn ability to adapt to the environment. The cognitive growth occurs through three interrelated processes: organiz ation, adaptation, and equilibrium. Organiz ation – Piaget’s term for the creation of categories or systems of knowledge. According to Piaget, people create increasingly complex cognitive structures called schemes, ways of organizing information about the world that govern the way the child thinks and behaves in a particular situation.  Adaptation – Piaget’s term for adjustment to new information about the environment. Assimilation – taking new information and incorporating it into existing cognitive structures. Accommodation – adjusting to one’s cognitive structures to fit the new information. Equilibration – tendency to seek a stable balance among cognitive elements, achieved through a balance between assimilation and accommodation.  Piaget’s Four Stages of Cognitive Development: 1. Sensorimotor (birth to 2 years) Infants use sensory and motor capabilities to explore and gain a basic understanding of the environment. At birth they have only innate reflexes with which to engage the world. By the end of the sensorimotor period, they are capable of complex sensorimotor coordination. Major developments: Infants acquire a primitive sense of “self ” and “others,” learn that objects continue to exist when they are out of sight (object permanence), and begin to internalize behavioral schemes to produce images or mental schemes. 2. Preoperational (2 to 7 years) Children use symbolism such as images and language to represent and understand various aspects of the environment. They respond to objects and events according to the way things appear to be. Thought is egocentric, which means that children think everyone sees the world in much the same way that they do. Major developments: ✓ Children become imaginative in their play activities. ✓ They gradually begin to recognize that other people may not always perceive the world as they do. 3. Concrete operations (7 to 11-12 years) Children acquire and use cognitive operations (mental activities that are components of logical thought). Major developments: ✓ Children are no longer fooled by appearances. ✓ By relying on cognitive operations, they understand the basic properties of and relations among objects and events in the everyday world. ✓ They are becoming much more proficient at inferring motives by observing others’ behavior and the circumstances in which it occurs. 4. Formal operations (11-12 years and beyond) Adolescents’ cognitive operations are reorganized in a way that permits them to operate on operations (think about thinking). Thought is now systematic and abstract. Major developments: ✓ Logical thinking is no longer limited to the concrete or the observable. ✓ Adolescents enjoy pondering hypothetical issues and, as a result, may become rather idealistic. ✓ They are capable of systematic, deductive reasoning that permits them to consider many possible solutions to a problem and to pick the correct answer. LEV VYGOTSKY’S SOCIOCULTURAL THEORY Lev Vygotsky (1896-1934) was a Russian psychologist who focused on the social and cultural processes that guide children’s cognitive development. Vygotsky’s sociocultural theory described cognitive growth as a collaborative process, where people learn through social interaction. He placed special emphasis on language, not merely as an expression of knowledge and thought but as an essential tool for learning and thinking about the world.  According to Vygotsky, adults or more advanced peers must help direct and organize a child’s learning before the child can master and internalize it. Zone of Proximal Development (ZPD) – term for the difference between what a child can do alone and what the child can do with help. Sensitive and effective instruction should be aimed at the ZPD and increase in complexity as the child’s abilities improve. Scaffolding – temporary support to help a child master a task. Vygotsky’s ideas have had an enormous impact on early childhood education, and they show great promise for promoting the development of self-regulation. INFORMATION-PROCESSING APPROACH Information-processing approach – approach to the study of cognitive development by observing and analyzing the mental processes involved in perceiving and handling information. Some information-processing theorists compare the brain to a computer: there are certain inputs (such as sensory impressions) and certain outputs (such as behaviors).  Like Piaget, information-processing theorists acknowledge that biological maturation is an important contributor to cognitive growth. They also contend that maturation of the brain and nervous system enables children and adolescents to process information faster. As a result, developing children become better at sustaining attention, at recognizing and storing task-relevant information, and at executing mental programs that allow them to operate on what they have stored to answer questions and solve problems. Yet, information-processing theorists are also keenly aware that the strategies that children develop for attending to and processing information are greatly influenced by their experiences. They proposed that cognitive development is a continuous process that is not stage-like.  PERSPECTIVE 4: CONTEXTUAL Contextual perspective – view of human development that sees the individual as inseparable from the social context. Urie Bronfenbrenner (1917-2005) was an American psychologist best known for having developed the bioecological theory, which emphasizes that the developing person is embedded in a series of environmental systems that interact with one another and with the person to influence development.  Bronfenbrenner (1979) begins by assuming that natural environments are the major source of influence on developing persons. He defined environment (or the natural ecology) as “a set of nested structures, each inside the next, like a set of Russian dolls.”  Here, individual difference variables such as age, sex, health, abilities, or temperament are present. The child is not seen as just an outcome of development; the child is an active shaper of development. To understand development, we must see the child within the context of the multiple environments surrounding her. 1.Microsystem It consists of the everyday environment of home, work, school, or neighborhood. It includes face-to-face interactions with siblings, parents, friends, classmates, or later in life, spouses, work colleagues, or employers. 2.Mesosystem It refers to the connections or interrelationships among such microsystems as homes, schools, and peer groups. It may include linkages between home and school or between the family and the peer group. 3.Exosystem It consists of contexts that children and adolescents are not a part of but that may nevertheless influence their development. 4.Macrosystem It consists of overarching cultural patterns, such as dominant beliefs, ideologies, and economic and political systems. 5.Chronosystem It represents the dimension of time. Time marches on, and as it does, changes occur. These can include changes in family composition, place of residence, or parents’ employment, as well as larger events such as wars, ideological shifts, or economic cycles. PERSPECTIVE 5: EVOLUTIONARY/ SOCIOBIOLOGICAL The evolutionary/sociobiological perspective proposed by E. O. Wilson (1929-2021) focuses on evolutionary and biological bases of behavior. Darwin’s theory of natural selection is one of the most important theoretical advances of modern science. Natural selection – differential survival and reproduction of different variants of member of a species, and is the tool the natural world uses to shape evolutionary processes. While it is commonly described as “survival of the fittest,” the key feature is in actuality reproductive success.  Individuals with more adaptive traits pass on more of those traits to future generations---”fit” characteristics are selected to be passed on, and others die out. These traits can be physical, behavioral, or psychological. Ethology – the study of distinct adaptive behaviors of animal species that have evolved to increase survival of the species. Ethologists compare animals of different species and seek to identify which behaviors are universal and which are specific to a particular species or modifiable by experience. Example: proximity-seeking or “ staying close to mommy” ---those baby animals that do not stay close to their mothers do not survive and therefore do not reproduce later in life.  Konrad Lorenz (1903-1989) was a European zoologist who helped put ethology into fame through his best- known research about the behavior of graylag geese, which will follow their mother once they hatch. In the study, Lorenz separated the eggs laid by one goose into two groups. He returned one group to the goose to be hatched by hers, while the other group was hatched in an incubator. The goslings belonging to the first group did as expected which was to follow their mother as soon as they hatched. But those in the second group which saw Lorenz when they first hatched, followed him everywhere as if he was their mother. This process was called by Lorenz as imprinting---the rapid, innate learning that includes attachment to the first moving object seen.  John Bowlby (1907-1990) was a British developmental psychologist and psychiatrist who demonstrated an important application of ethological theory to human development through his attachment theory. He emphasized that attachment to a caregiver during the first year of life has significant consequences all through life span. He believed that if this attachment is positive and secure, the individual will probably have positive development in childhood and adulthood. But if the attachment is negative and insecure, life span development will probably not be optimal. An Eclectic Orientation Approach Although each theory has contributed to our understanding of development, no single theory can completely explain the rich complexity of life-span development. All theories are indeed helpful guides, but it is not right to only depend on a single theory with regard to explaining development. Rather, an eclectic theoretical orientation must be considered. You must not follow any one theoretical approach, but instead select the best features from each theory. Through this, you can perceive the study of development with different theorists having different assumptions, emphasizing different realistic problems, and using different approaches to discover information.  RESEARCH METHODS Researchers in human development work within two methodological traditions: 1. Quantitative research It deals with objectively measurable data. It is based on the scientific method, which refers to the use of objective and replicable methods to gather data for the purpose of testing a theory or hypothesis.  Steps in Scientific Method: 1. Identification of a problem to be studied, often on the basis of a theory or of previous research; 2. Formulation of hypotheses to be tested by research; 3. Collection of data; 4. Statistical analysis of the data to determine whether they support the hypothesis; 5. Formation of tentative conclusions; and 6. Dissemination of findings so other observers can check, learn from, analyze, repeat, and build on the results. 2. Qualitative research It focuses on nonnumerical data, such as subjective experiences, feelings, or beliefs. Goal: to understand the “story” of the event. It is more flexible and informal, and these researchers might It might be more interested in gathering and exploring large amounts of data to see what hypotheses emerge than in running statistical analyses on numerical data.  SAMPLING Sample – group of participants chosen to represent the entire population under study. Random selection – selection of a sample in such a way that each person in a population has an equal and independent chance of being chosen. In qualitative research, samples tend to be focused rather than random. FORMS OF DATA COLLECTION 1. Self-Reports a. Structured interview or structured questionnaire – a technique in which all participants are asked the same questions in precisely the same order so that the responses of different participants can be compared. FORMS OF DATA COLLECTION Diary study – a questionnaire method in which participants write answers to specified questions in a diary or notebook, either at specified times or when prompted by an electronic pager. FORMS OF DATA COLLECTION 1. Self-Reports b. Clinical method – a type of interview in which a participant’s response to each successive question (or problem) determines what the investigator will ask next. FORMS OF DATA COLLECTION 2. Observational Mtethod a. Naturalistic observation – a method in which a researcher tests hypotheses by observing people as they engage in everyday activities in their natural habitats. Observer influence – tendency of participants to react to an observer’s presence by behaving in unusual ways. Time-sampling – a procedure in which the investigator records the frequencies with which individuals display particular behaviors during the brief time intervals each is observed. FORMS OF DATA COLLECTION 2. Observational Method b. Structured observation – an observational method in which the investigator cues the behavior of interest and observes participants’ responses in a laboratory. FORMS OF DATA COLLECTION 3.Case Studies Case study – a research method in which the investigator gathers extensive information about the life of an individual and then tests developmental hypotheses by analyzing the events of the person’s life history. FORMS OF DATA COLLECTION 4. Ethnography – a method in which the researcher seeks to understand the unique values, traditions, and social processes of a culture or subculture by living with its members and making extensive observations and notes. FORMS OF DATA COLLECTION 5. Psychophysiological Methods - methods that measure the relationships between physiological processes and aspects of children’s physical, cognitive, social, or emotional behavior/ development. GENERAL RESEARCH DESIGNS 1. Correlational – a type of research design that indicates the strength of associations among variables. 2. Laboratory experiment – a research design in which the investigator introduces some change in the participant’s environment and then measures the effect of that change on the participant’s behavior. 3. Field experiment – an experiment that takes place in a naturalistic setting such as home, school, or a playground. 4. Natural (or quasi-) experiment – a study in which the investigator measures the impact of some naturally occurring event that is assumed to affect people’s lives. DEVELOPMENTAL RESEARCH DESIGNS 1.Cross-sectional It is a research design in which subjects from different age groups are studied at the same point in time. Cohort – a group of people of the same age who are exposed to a similar cultural environments and historical events as they are growing up. DEVELOPMENTAL RESEARCH DESIGNS 2.Longitudinal It is a research design in which one group of subjects is studied repeatedly over a period of time. The time spend may be relatively brief (6 months – 1 year) or it may be very long, spanning a lifetime. DEVELOPMENTAL RESEARCH DESIGNS 3.Sequential It is a research design in which subjects from different age groups are studied repeatedly over a period of months or years. It combines the best features of cross-sectional and longitudinal studies.  E T H I C S O F RE S E A RC H Guidelines of the American Psychological Association (APA, 2002) cover such issues as: 1. Informed consent 2. Avoidance of deception 3. Protection of participants from harm and loss of dignity 4. Guarantees of privacy and confidentiality 5. Right to decline or withdraw from an experiment at any time 6. Responsibility of investigators to correct any undesirable effects  In resolving ethical dilemmas, researchers should be guided by three principles: 1. Beneficence, the obligation to maximize potential benefits to participants and to minimize potential harm. 2. Respect for participants’ autonomy and protection of those who are unable to exercise their own judgment. 3. Justice, the inclusion of diverse groups together with sensitivity to any special impact the research may have on them. Developmental psychologists must be particularly careful as their research frequently involves vulnerable individuals, such as infants or children.  The Society for Research in Child Development (2007) has developed standards for age-appropriate treatment of children in research, covering such principles as avoidance of physical or psychological harm, obtaining the child’s assent as well as a parent’s or guardian’s informed consent, and responsibility to follow up on any information that could jeopardize the child’s well-being.