The correct answer appears first and is boldface.

1. b. A test high in reliability would result in similar scores when taken more than once.

a Validity refers to the concept that the test is measuring what the researchers think it is measuring.

c An operational definition is the precise, specific way a researcher measures a variable.

d When two researchers score the same result, their results are compared to determine inter-rater reliability.

2. b. A high inter-rater reliability would indicate that the students were consistently observing and measuring the same behavior.

a. A low inter-rater reliability would indicate that the two students had very different results.

c. Validity refers to the extent to which an assessment procedure actually measures a variable under consideration. Validity cannot be assessed by comparing two raters' scores.

d. Validity refers to the extent to which an assessment procedure actually measures a variable under consideration. Validity cannot be assessed by comparing two raters' scores.

3. c. Because the experimenter does not manipulate variables during naturalistic observations, causal relationships between variables cannot always be determined.

a. In the naturalistic observational approach to collecting data, children are not approached with questions; researchers simply observe and record data from a real-world setting.

b. As long as the researcher is inconspicuous while making her observations, there is no reason to believe that a child will not act normally when in his usual surroundings.

d. In fact, the opposite is true. Naturalistic observations are especially useful when a topic has not been extensively researched.

4. a. In the structured interview, each child is given the same sequence of questions; thus, it is ideal for Miguel's research.

b. Although the clinical method is useful, the open-ended questions that it uses make it more difficult to compare responses among children.

c. The experimental method is not appropriate, since Miguel does not need to manipulate any variables and is not considering causal factors.

d. Naturalistic observation is unlikely to yield much information concerning children's attitudes toward death and dying because children rarely discuss such matters. It would be better to ask the children questions directly.

5. a. Unlike the structured interview, which adheres to a rigid protocol of predetermined questions, the clinical method allows the investigator to modify questions in reaction to the child's responses. Piaget was well-known for using this method.

b. All interview methods obtain information about what a child knows by asking the child directly rather than by simply observing her or him.

c. Because the interview method involves talking with individual children, the interview cannot be administered to a group of children simultaneously. The questionnaire can be administered to a large number of children at the same time.

d. The question of why children know what they know is a cause-and-effect question. Although the interview method could provide some possible reasons children have a certain piece of knowledge, the interview cannot determine the actual source of the knowledge.

6. c. A meta-analysis of all of the previously published research can be very useful in determining whether moderate alcohol consumption has an important effect on infant behavioral development.

a. Harlene should not abandon this area of research, since there are still many unanswered questions to be addressed. The business of science is to provide answers to questions of interest.

b. Given the topic, the studies Harlene reviewed were probably mostly correlational. Conducting another correlational study is unlikely to resolve the issue.

d. Observing mothers and infants in their normal environment is unlikely to provide any useful information concerning the effects of alcohol on infant development.

7. b. A negative correlation is when two variables go in opposite directions. In this example, grades decreased as the amount of alcohol increased.

a A positive correlation is when two variables go in the same direction.

c A zero correlation is when two variables have no relationship to one another, but there is clearly a relationship described in the example.

d There is no such term as a causal correlation; causality can not be determined from correlations.

8. c. As a result of random assignment in experimental designs, a distinct advantage is that cause-and-effect relationships among variables can be identified.

a. One criterion for scientific experimental research is that all data must be collected objectively and in an unbiased manner.

b. Although a major advantage of experimental research is that it can identify cause-and-effect relationships among variables, results obtained from a scientific study are not always easily interpreted.

d. One criticism of experimental research designs is that they do not capture the complexities of the changes that occur during development.

9. c. Tonya needs to manipulate exposure to video games (the independent variable) and measure problem-solving ability (the dependent variable) to determine whether there is a causal relationship between the two variables.

a. A correlational study would indicate whether video game playing is related to better problem-solving abilities, but it would not be able to indicate a causal relationship between the two variables.

b. To test her hypothesis, Tonya needs to manipulate the children's exposure to video games. A naturalistic observation study does not permit manipulation of variables.

d. Simply interviewing children who play video games is unlikely to provide support for her hypothesis. Tonya needs to manipulate children's exposure to video games and measure their problem-solving ability to determine whether there is a causal relationship between the two variables.

10. b. The type of film viewed (the independent variable) is suspected of influencing toddlers' successful use of the toilet (the dependent variable).

a. The number of children who are toilet trained by the end of the study is the dependent variable.

c. Random assignment of participants to groups is an important method of control, but it is not the independent variable.

d. The number of toddlers per group is not an independent variable in an experiment.

11. c. The video images shown to the infants comprise the independent variable. Variations in the infant behaviors are predicted to be a function of which image is being shown.

a. Establishing a baseline of behavior is important for single-case designs, but baseline variable is not a term used in an experimental design.

b. There is no term called experimental variable in an experimental design.

d. The infants' responses are the dependent variables because they are assumed to be affected by the visual image being shown.

12. b. Longitudinal studies are conducted to examine the same individuals repeatedly over a period of time, usually years, to determine the stability of human characteristics.

a. In cross-sectional studies, individuals of different ages are examined at the same point in time.

c. In a quasi-experiment, the assignment of participants to experimental groups is determined by their natural experience. No information is given about the nature of group assignment here.

d. A cohort effect is the result of characteristics shared by individuals growing up in a given sociohistorical context that influences their developmental outcomes.

13. d. Researchers must often translate instructions and materials for psychological research. Thus, to compare the performance of groups of individuals from different cultures, the tasks must be similar and of equivalent forms.

a. Although longitudinal studies may be more difficult in some cultures than in others, researchers interested in cross-cultural research are not limited to cross-sectional studies.

b. One of the major reasons to carry out cross-cultural research is to help determine whether behaviors are similar and perhaps largely shaped by biological factors, regardless of the child's cultural background.

c. Someone unfamiliar with or outside the culture may not be able to obtain reliable and valid data concerning the behavior of individuals from another culture.

14. b. A participant (or the child's parent) must sign an informed consent form before participating in a study.

a. The debriefings occur at the completion of a study, not at the beginning, and only if the parent has not been told about all of the purposes of the study.

c. Although this may sound like a good idea, the informed consent form must be signed before participating in an experiment.

d. Some researchers do provide participants with a small sum of money to cover travel expenses after participating in the study, but that is unlikely to be the first order of business when they arrive at the laboratory.

15. b. All psychologists who conduct research are required to abide by a set of criteria established for the conduct of ethical research.

a. Experimental studies are especially valuable for identifying the underlying causes of behavior; however, much valuable information about development can be obtained using other research designs.

c. Researchers may choose from among several different research designs to study development, some of which may be better than others for answering certain questions about development.

d. Although research that involves deception with children is generally not preferred, it may be warranted and approved by review committees in exceptional circumstances. However, researchers are required to debrief participants in such studies.

16. c. A correlational design is conducted when a researcher can not manipulate variables. It would be unethical to randomly assign any women to use cocaine while pregnant.

a. A cross-sectional design is used to determine differences between age groups, by examining several different groups of participants.

b An experimental design would be unethical in this situation.

d A case-study examines just one or two participants who have unusual backgrounds or abilities.

17. c. Strength of a correlation depends on the absolute number. In this example, -0.7 is the highest absolute value (the sign of the correlation is not related to the strength).

a A correlation of zero means there is no relationship between the variables.

b This correlation must be a mistake, as correlations can only range from +1 to -1.

d A +0.5 is a weaker correlation, as sign does not matter when determining strength.

18. b. A cross-sectional study examines different groups of participants at different ages.

a A meta-analytic study simply combines the results of prior research.

c A longitudinal study follows the same group of participants over time. Since Jennifer was able to test each grade, she clearly did not follow the same participants.

d The sequential design combines both the cross-sectional and longitudinal. If Jennifer went back years later and re-tested the participants, she would then be conducting a sequential design.