AP Psych Unit 5 Research Methods

Flashcards based on David G. Myers' Psychology for AP, 2e, focusing on research methods and statistical reasoning.

Hindsight

The tendency to believe, after learning an outcome, that one would have foreseen it. For example, after a sports game, saying 'I knew they were going to win!' even if you weren't sure before the game.

Thinking

Thinking that examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions. For example, questioning the validity of a news article before sharing it.

Theory

An explanation using an integrated set of principles that organizes observations and predicts behaviors or events. For example, the theory of evolution explains the diversity of life on Earth.

Hypothesis

A testable prediction, often implied by a theory. For example, 'If students study before a test, then they will get a better grade.'

Definition

A carefully worded statement of the exact procedures used in a research study. For example, defining 'sleep deprivation' as 'less than 6 hours of sleep per night for three consecutive nights' in a study.

Replication

Repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances. For example, conducting the Milgram experiment in different countries to see if obedience rates vary.

Case

A descriptive technique in which one individual or group is studied in depth in the hope of revealing universal principles. For example, studying a person with a rare brain disorder to understand how that part of the brain works.

Observation

Observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation. For example, watching children play at a playground to study social interactions.

Survey

A technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group. For example, polling voters to predict the outcome of an election.

Bias

A flawed sampling process that produces an unrepresentative sample. For example, surveying only people who visit a specific website to understand the general population's views.

Population

All the cases in a group being studied, from which samples may be drawn. For example, if you are studying American voters, the population is all registered voters in America.

Sample

A sample that fairly represents a population because each member has an equal chance of inclusion. For example, drawing names from a hat to select participants for a study.

Correlation

A measure of the extent to which two factors change together, and thus of how well either factor predicts the other. For example, noticing that as ice cream sales increase, so do crime rates.

Coefficient

A statistical index of the relationship between two things (from -1.0 to +1.0). For example, a correlation coefficient of +0.8 indicates a strong positive correlation.

Scatterplot

A graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. For example, a scatterplot might show a positive correlation between study time and test scores.

Illusory

The perception of a relationship where none exists. For example, believing that it always rains after you wash your car.

Experiment

A research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable). By random assignment of participants, the experimenter aims to control other relevant factors. For example, testing whether a new drug reduces symptoms of depression.

Experimental

In an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable. For example, patients who receive the actual medication in a drug trial.

Control

In an experiment, the group that is NOT exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment. For example, patients who receive a placebo in a drug trial.

Assignment

Assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between those assigned to the different groups. For example, using a random number generator to assign participants to different treatment groups.

Double-Blind

An experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or the placebo. For example, in a drug trial, neither the patients nor the doctors know who is receiving the actual drug.

Placebo

Experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent. For example, a sugar pill that reduces pain because the patient believes it is a real painkiller.

Independent

The experimental factor that is manipulated; the variable whose effect is being studied. For example, the dosage of a drug in a drug trial.

Confounding

A factor other than the independent variable that might produce an effect in an experiment. For example, if you are testing the effect of a new teaching method, the students' prior knowledge could be a confounding variable.

Dependent

The outcome factor; the variable that may change in response to manipulations of the independent variable. For example, test scores in a study examining the effectiveness of a new teaching method.

Validity

The extent to which a test or experiment measures or predicts what it is supposed to. For example, a valid IQ test should accurately measure a person's intelligence.

Descriptive

Numerical data used to measure and describe characteristics of groups. Include measures of central tendency and measures of variability. For example, calculating the average age of participants in a study.

Histogram

A bar graph depicting a frequency distribution. For example, a histogram showing the distribution of grades on a test.

Mode

The most frequently occurring score(s) in a distribution. For example, in the dataset (1, 2, 2, 3, 4), the mode is 2.

Mean

The arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores. For example, the mean of (1, 2, 3, 4, 5) is (1+2+3+4+5)/5 = 3.

Median

The middle score in a distribution; half the scores are above it and half are below it. For example, in the dataset (1, 2, 3, 4, 5), the median is 3.

Skewed

A representation of scores that lack symmetry around their average value. For example, income distribution in a country is often skewed, with a long tail of high earners.

Range

The difference between the highest and lowest score in a distribution. For example, in the dataset (1, 2, 3, 4, 5), the range is 5 - 1 = 4.

Deviation

A computed measure of how much scores vary around the mean score. For example, a small standard deviation indicates that the scores are clustered closely around the mean.

Normal

A symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean (68 percent fall within one standard deviation of it) and fewer and fewer near the extremes. For example, the distribution of heights in a population often follows a normal curve.

Inferential

Numerical data that allow one to generalize – to infer from sample data the probability of something being true to a population. For example, using a survey of voters to predict the outcome of an election.

Significance

A statistical statement of how likely it is that an obtained result occurred by chance. For example, a p-value of 0.05 means there is a 5% chance that the results occurred by chance.

Culture

The enduring behaviors, ideas, attitudes, values, and traditions shared by a group of people and transmitted from one generation to the next. For example, the traditions and customs of a particular country or region.

Consent

An ethical principle that research participants be told enough to enable them to choose whether they wish to participate. For example, telling participants about the risks and benefits of a study before they agree to join.

Debriefing

The postexperimental explanation of a study, including its purpose and any deceptions, to its participants. For example, explaining to participants after a study that they were deceived about the true purpose of the study.