AP Psychology Unit 0: Research Methods and Data Interpretation

Sampling Bias

Flawed sampling process that produces an unrepresentative sample

Hindsight Bias

The tendency to believe, after learning an outcome, that we would have foreseen it

Sampling Bias

Flawed sampling process that produces an unrepresentative sample

Hindsight Bias

The tendency to believe, after learning an outcome, that we would have foreseen it

Confirmation Bias

Ignoring or finding fault with information that does not fit our opinions, and seeking information with which we agree

Social Desirability Bias

Tendency to underreport socially undesirable attitudes and behaviors and to over report more desirable attributes

Theory

Uses observations to explain and predict behavior or events

Hypothesis

Testable prediction

The Scientific Method

1. Develop a hypothesis

2. Perform controlled test

3. Gather objective data

4. Analyze results

5. Publish, critic, and replicate results

Population

Total group of people/animals to draw from

Random Sample/Selection

Selection of subjects who will be chosen from the population to participate

Random Assignment

Likelihood that all participants in a group or a sample have an equal chance of being assigned to different conditions within the study

Experimental Group

Receives intervention being tested

(ie; drug, vaccine)

Control Group

Often given placebo or nothing

Double Blind

An experimental procedure in which both researchers and participants are uninformed about the nature of the independent variable being administered

Operational Definition

Carefully worded statement of exact procedures used in a research study

Naturalistic Observation

Observing subjects in their own environment who are unaware that they are being watched

Correlational Studies

Mainly statistical in nature. Determines relationship for correlation between two variables

Positive correlation

Means the variables vary in the same direction

Negative correlation

Means the variables vary in opposite directions

Case Studies

A process or record of research in which detailed consideration is given to the development of a particular person, group, or situation over a period of time

Survey Research

Method in which questions are asked to participants

• widely used to observe attitudes, opinions, and reported behaviors

Meta Analysis

Synthesizing results of multiple studies of a phenomenon into a single result by combining the effect size estimates from each study into a single estimate of the combined effect size or into a distribution of effect sizes

Descriptive statistics

Numerical data used to measure and describe characteristics of groups

Inferential statistics

Numerical data that allow one to generalize characteristics to a population

Median

Middle score of distribution

(After our in order)

Mean

Average set of scores

Mode

Most frequently recurring score

Standard Deviation

Measure of variability mentioning scores of distribution and the mean. Used to assess how far the values are spread below and above the mean

Z score

How far a number is below or above the mean for standard deviation

Range

The difference between the highest and lowest scores in a distribution

Regression to the mean

The tendency for extreme scores or events to fall back toward the average.

The correlation coefficient

Describes how well two variables are correlated

• Ranges from -1 to +1

  • The closer to -1 or +1 the stronger the correlation, if coefficient is 0, there is no correlation

Positive Correlation

As one variable increases, the other variable increases

Negative Correlation

As one variable increases, the other decreases

No Correlation

There is no connection between the two variables

Illusory correlations

Perceive a relationship where none exist

Frequency distribution

Breakdown of how the scores fall into different categories or ranges

Normal distribution

Shows how traits are distributed throughout a population usually within the use of a bell curve

68%

Data falls within one standard deviation about the mean

95%

Data falls within two standard deviations about the mean

Representative samples

Better than biased samples, which often come in the form of memorable and exceptional cases

(Ex: Conducting an experiment on student knowledge of UHS athletics, only asking members of the cheer team would be an unrepresentative sample)

Null Hypothesis

Predicts that nothing will happen

Alternate hypothesis

Predicts something will happen