A testable prediction about what should happen if an idea is correct, often phrased as an if-then statement, is called what?
Hypothesis
✓
Theory
Operational definition
Confounding variable
Correct Answer
Hypothesis
A hypothesis is a specific, testable prediction, usually derived from a broader theory. A theory is a well-developed set of ideas that explains many observations and is too broad to test all at once. An operational definition describes how a variable will be measured. A confounding variable is an outside factor that can distort the relationship between the variables being studied.
Category: Scientific Reasoning
Question 2
A researcher starts with a general theory about memory and uses it to derive a specific prediction that she then tests in the lab. Which kind of reasoning is she using?
Inductive reasoning
Deductive reasoning
✓
Confirmation bias
Introspection
Correct Answer
Deductive reasoning
Deductive reasoning moves from a generalization to specific, logical conclusions that can then be tested against observations. Inductive reasoning works the other way, building generalizations from specific observations. Confirmation bias is the tendency to favor evidence that supports what one already believes. Introspection is the examination of one's own conscious experience.
Category: Scientific Reasoning
Question 3
A major criticism of Freud's concepts of the id, ego and superego is that no observation could ever show them to be wrong. Which property of a scientific idea do they lack?
Reliability
Generalizability
Falsifiability
✓
Ecological validity
Correct Answer
Falsifiability
Falsifiability means an idea is stated so that evidence could, in principle, show it to be incorrect, and scientific hypotheses must have this property. Reliability is the consistency of a measurement. Generalizability is how well findings from a sample apply to a larger population. Ecological validity is how closely a study's setting resembles real life.
Category: Scientific Reasoning
Question 4
A researcher spends years studying a single pair of rare conjoined twins in great depth. Which research method is this?
Survey
Archival research
Naturalistic observation
Case study
✓
Correct Answer
Case study
A case study, also called a clinical study, is an in-depth look at one person or a small number of individuals, and it is useful for rare conditions even though the results are hard to generalize. A survey collects answers to a set of questions from many participants. Archival research analyzes existing records. Naturalistic observation records behavior in its everyday setting without interfering.
Category: Descriptive Methods
Question 5
Jane Goodall spent decades watching wild chimpanzees in Africa without trying to change their behavior. Which research method did she use?
Naturalistic observation
✓
Structured observation
Experiment
Cross-sectional research
Correct Answer
Naturalistic observation
Naturalistic observation means watching behavior where it normally happens, which gives the study high ecological validity. Structured observation has people or animals complete specific tasks in a set situation, such as a laboratory. An experiment manipulates a variable to test cause and effect. Cross-sectional research compares different age groups at one point in time.
Category: Descriptive Methods
Question 6
Two observers separately code the same video of children at play, and the researchers check how closely the two sets of records agree. What are the researchers measuring?
Test-retest reliability
Inter-rater reliability
✓
Predictive validity
Ecological validity
Correct Answer
Inter-rater reliability
Inter-rater reliability is the consistency of observations made by different observers of the same events, and checking it helps guard against observer bias. Test-retest reliability is the consistency of one measure given to the same people at two different times. Predictive validity is how well a measure forecasts a later outcome. Ecological validity is how realistic a study's setting is.
Category: Descriptive Methods
Question 7
A researcher who wants to draw conclusions about all college students in the United States gives a questionnaire to 500 of them. What are the 500 students?
The population
A cohort
The sample
✓
The control group
Correct Answer
The sample
A sample is the subset of individuals actually selected for study from the larger group of interest. The population is the entire group the researcher wants to draw conclusions about, here all U.S. college students. A cohort is a group of people born around the same time who share generational experiences. The control group is the group in an experiment that does not receive the treatment.
Category: Descriptive Methods
Question 8
To learn how long students take to finish college, a researcher reviews ten years of existing enrollment and graduation records without contacting any students. Which method is this?
Longitudinal research
Naturalistic observation
Case study
Archival research
✓
Correct Answer
Archival research
Archival research analyzes records or data sets that already exist, so the researcher never interacts with participants but also cannot control how the data were collected. Longitudinal research follows the same participants over time with new testing. Naturalistic observation watches behavior as it happens. A case study examines one or a few individuals in depth.
Category: Descriptive Methods
Question 9
A researcher compares the eating habits of separate groups of 20-, 30- and 40-year-olds, all measured during the same month. Which design is this?
Cross-sectional research
✓
Longitudinal research
Archival research
Experimental research
Correct Answer
Cross-sectional research
Cross-sectional research compares different segments of a population at a single point in time, which is fast but vulnerable to cohort effects. Longitudinal research would test the same people repeatedly as they aged from 20 to 40. Archival research uses existing records rather than new measurement. Experimental research manipulates an independent variable, which age cannot be.
Category: Descriptive Methods
Question 10
In a 20-year study that tests the same people every few years, many participants drop out before the study ends. What is this loss of participants called?
Observer bias
Attrition
✓
Cohort effect
Sampling error
Correct Answer
Attrition
Attrition is the reduction in the number of participants over time, and it grows the longer a longitudinal study runs. Observer bias is the skewing of observations by the observer's expectations. A cohort effect is a difference caused by generational experience rather than age. Sampling error is the chance difference between a sample and the population it was drawn from.
Category: Descriptive Methods
Question 11
In a data set, which measure of central tendency is the score that occurs most often?
Median
Mean
Mode
✓
Range
Correct Answer
Mode
The mode is the most frequently occurring value in a data set. The median is the middle score when scores are listed in order. The mean is the arithmetic average and is strongly affected by extreme scores. The range is the difference between the highest and lowest scores and describes spread, not a typical value.
Category: Descriptive Methods
Question 12
Which of these correlation coefficients indicates the strongest relationship between two variables?
+0.40
+0.10
0.00
-0.85
✓
Correct Answer
-0.85
The strength of a correlation depends on how close the coefficient is to -1 or +1, and the sign shows only the direction, so -0.85 is the strongest. A value of +0.40 is a moderate positive relationship. A value of +0.10 is a very weak positive relationship. A value of 0.00 indicates no relationship at all.
Category: Correlation
Question 13
As the hours people sleep go up, their reported daytime tiredness goes down. Which kind of relationship is this?
Negative correlation
✓
Positive correlation
Zero correlation
Illusory correlation
Correct Answer
Negative correlation
In a negative correlation the two variables move in opposite directions, so more of one goes with less of the other. A positive correlation means both variables rise or fall together, as with height and weight. A zero correlation means the variables are unrelated. An illusory correlation is a relationship people believe in that does not actually exist.
Category: Correlation
Question 14
Ice cream sales and crime rates both rise in the summer, but hot weather likely drives both. In this example, temperature is best described as what?
Dependent variable
Confounding variable
✓
Independent variable
Operational definition
Correct Answer
Confounding variable
A confounding variable is an outside factor that influences both variables being studied and creates a misleading appearance that one causes the other. A dependent variable is the outcome measured in an experiment. An independent variable is the factor an experimenter deliberately manipulates. An operational definition is a precise description of how a variable is measured.
Category: Correlation
Question 15
Many people are convinced that a full moon makes people behave strangely, even though studies find no such relationship. What is this belief an example of?
Positive correlation
Experimenter bias
Illusory correlation
✓
Observer bias
Correct Answer
Illusory correlation
An illusory correlation is the perception of a relationship that does not actually exist, often kept alive by remembering only the cases that fit. A positive correlation is a real relationship in which two variables rise together. Experimenter bias is a researcher's expectations skewing an experiment's results. Observer bias is an observer's expectations distorting what is recorded during observation.
Category: Correlation
Question 16
Students are randomly assigned to learn algebra either from a computer program or from a teacher, and all then take the same test. In this study, the learning method is what?
Dependent variable
Confounding variable
Control group
Independent variable
✓
Correct Answer
Independent variable
The independent variable is the factor the experimenter manipulates, here the method of instruction. The dependent variable is the outcome measured to see the effect, here the test scores. A confounding variable is an uncontrolled outside factor, which random assignment helps prevent. The control group is the students taught by the teacher, a group of people rather than a variable.
Category: Experiments
Question 17
In a drug trial, neither the participants nor the researchers who interact with them know who is receiving the real medication. What kind of study is this?
Double-blind study
✓
Single-blind study
Case study
Cross-sectional study
Correct Answer
Double-blind study
A double-blind study hides group assignments from both participants and researchers, which controls for both participant expectations and experimenter bias. In a single-blind study only the participants are unaware of their group. A case study is an in-depth look at one or a few individuals, with no comparison groups. A cross-sectional study compares different age groups at one time.
Category: Experiments
Question 18
Why do researchers use random assignment when placing participants into experimental and control groups?
To ensure the sample matches the population
To make preexisting group differences unlikely
✓
To let participants choose their condition
To keep participants unaware of the hypothesis
Correct Answer
To make preexisting group differences unlikely
Random assignment gives every participant an equal chance of being in each group, so the groups are likely to be similar before treatment and any later difference can be credited to the independent variable. Ensuring the sample matches the population is the job of random sampling, not assignment. Letting participants choose their condition would invite systematic differences. Keeping participants unaware of the hypothesis is the purpose of blinding or deception.
Category: Experiments
Question 19
A kitchen scale reads exactly 2 pounds too heavy every time the same object is weighed. How should this scale be described?
Valid but not reliable
Neither reliable nor valid
Reliable but not valid
✓
Valid and reliable
Correct Answer
Reliable but not valid
The scale is reliable because it gives the same result every time, but it is not valid because it does not measure true weight accurately. Valid but not reliable is not possible, because a measure that varies from use to use cannot consistently measure the true value. Neither reliable nor valid would describe a scale with random, inconsistent errors. Valid and reliable would require readings that are both consistent and correct.
Category: Evaluating Research
Question 20
Before a university study involving human participants can begin, its proposal generally must be approved by which body?
An animal care and use committee
A journal's peer reviewers
A state licensing board
An institutional review board
✓
Correct Answer
An institutional review board
An institutional review board, or IRB, is a committee of administrators, scientists and community members that reviews human research proposals for participant safety and dignity, and institutions receiving federal research support must have one. An animal care and use committee reviews research with animals, not humans. A journal's peer reviewers evaluate finished studies before publication. A state licensing board regulates who may practice as a psychologist.
Category: Research Ethics