PSYC 3620: Developmental Psychology Ch.3 Vocabulary1. basic research: research that has the primary goal of adding to our body of knowledge rather than having immediate application2. applied research: research that has the primary goal of solving problems or improving the human condition3. scientific method: the process of formulating & testing hypotheses in a rigorous & objective manner4. hypothesis: a prediction, often based on theoretical ideas or observations, that is tested by the scientific method5. operationalize: to define a concept in a way that allows it to be measured6. reliability: the ability of a measure to produce consistent results7. validity: the ability of a research tool to accurately measure what it purports to measure8. interrater reliability: a measure of consistency in the data gathered by multiple observers9. generalize: to draw inferences from the findings of research on a specific sample about a larger group or population10. population: a set that includes everyone in a category of individuals that we are interested in studying11. representative sample: a group of participants in a research study who have individual characteristics in the same distribution that exists in the population12. event sample: a data collection technique in which a researcher records information about all occurrences of a coherent set of behaviors being investigated13. time sample: a data collection technique in which a researcher observes an individual for a predetermined period of time & records the occurrence of specific behaviors of interest to the research during that period14. checklist: a prepared list of behaviors, characteristics or judgments used by observers to assess a child’s development15. survey: a data collection technique that asks respondents to answer a common set of questions16. questionnaires: a written form of a survey17. interviews: a data technique in which an interviewer poses questions to a respondent18. clinical interview: an interview technique in which the interviewer can deviate from a standard set of questions to gather addition information19. norm: the average or typical performance of an individual of a given age on a test20. case study: an in-depth study of a single individual or small group of individuals which uses multiple methods of study21. experimental group: the group in an experiment that gets the special treatment that is of interest to the researcher22. control group: the group in an experiment that does not get the special treatment & provides a baseline against which the experimental group can be compared23. random assignment: assigning participants to the experimental & control groups by chance so that the groups will not systematically differ from each other24. variable: a characteristic that can be measured & that can have different values25. independent variable: the variable in an experiment that the researcher manipulates26. dependent variable: the outcome of interest to the researcher that is measured at the end of an experiment27. natural or “quasi” experiement: research in which the members of the group are selected because they represent different “treatment” conditions28. correlation: a measure of the strength & direction of the relationship between two variables29. positive correlation: a correlation in which increases in one variable are associated with increases in another variable30. negative correlation: a correlation in which increases in one variable are associated with decreases in another variable31. longitudinal design: a research design that follows one group of individuals over time & looks at the same or similar measures at each point of testing32. attrition: the loss of participants over the course of a longitudinal study33. sample bias: changes in the makeup of the sample in a longitudinal or cross-sequential study that make the sample less representative over time34. cross-sectional design: a research design that uses multiple groups of participants who representthe age span of interest to the researcher35. cohort effect: differences between groups in a cross-sectional or cross-sequential study that are attributable to the fact that the participants have had different life experiences36. cross-sequential design: a research design that uses multiple groups of participants & follows them over a period of time, with the beginning age of each group being the ending age of another group37. null hypothesis: the hypothesis tested by an experiment that there will be no difference in the outcome for the groups in an experiment38. meta-analysis: a statistical procedure that combines data from different studies to determine whether there is a consistent pattern of findings across studies39. informed consent: informing research participants of the risks & benefits of participating in the research & guaranteeing them the right to withdraw from participation if they