(2025) AP Psychology U0 Science Practices

Chapter 1: History of Psychology

Different Psychological Perspectives

Humanistic Perspective

• Stresses individual choice and free will

• Believes that we choose our own behaviors, and they are influenced by spiritual, physiological and emotional needs.

  • Ex. Humanistic theorists believe introverts choose to maintain less social contact because that is what they need to fulfill their social needs

• Humanistic theories are not easily tested scientifically and are seen as historic perspectives, but are still employed by some therapists to aid clients in overcoming obstacles

Examples:

Abraham Maslow

Carl Rogers

Psychodynamic Perspective

• Believes that our unconscious mind controls most of our actions and thoughts

• Believes we must analyze our minds through dream interpretation, free association and other techniques

  • Ex. Psychodynamic theorists would say that an introverted person would stray from social events due to repressed childhood trauma or emotions involving anxiety in a social setting.

Biopsychology/Neuroscience Perspective

• Believe that our behaviors or reactions are caused by genes, hormones or neurotransmitters in the brain.

  • Ex. Might explain extrovertedness as caused by genetics from parents which cause an abundance of certain neurotransmitters in the brain.

Evolutionary Perspective

• Examine human thoughts in terms of natural selection

  • Ex. Might explain the tendency to be extroverted as a survival advantage. They may make friends with ‘allies’ which could improve their chances at survival

Behavioral Perspective

• Explain human thought and behavior in terms of conditioning

• Looks at behavior that is observable, against different types of stimuli

  • Ex. might explain extroversion in terms of reward and punishment;

• would look to the environment for reasons why a person would be extroverted.

Cognitive Perspective

• Explain human behavior in terms of how we interpret, remember and process environmental events

• Rules we use to see the world are important to how we behave

  • Ex. would explain extroverted behavior as dependent on how the person is interpreting their environment

  • says that an extrovert would behave as such if they interpreted the world in a way that being outgoing makes sense

Sociocultural Perspective

• Look at how thoughts and behaviors vary among cultures

  • Ex. would explain extroversion by examining cultural factors and rules about social interaction

Biopsychosocial Perspective

• Explores the biological influence on our behaviors and patterns

  • Ex. would explain extroversion as a conditioned response or a genetic predisposition.

Chapter 2: Research Methods

Hindsight bias: tendency upon hearing research findings to think that you knew it al along.

Confirmation bias: tendency to pay more attention to what contributes to and supports our ideas rather than what contradicts it.

Overconfidence: a well-established bias in which a person's subjective confidence in their judgments is reliably greater than the objective accuracy of those judgments,

Quantitative research: a research type focusing on statistical and numerical data.

Qualitative research: a research type focusing on more complex textual responses, looking for key themes.

Hypothesis: a statement expressing a relationship between two variables; otherwise known as an educated guess made by researchers or scientists.

Dependent variable: a variable that depends on the outcome of another; also known as the variable in the experiment that changes and is tested.

Independent variable: a variable that remains unchanged during an experiment; otherwise a variable that produces a change/ impacts the dependent variable.

Falsifiable: meaning that it must be possible to gather data that could controvert the hypothesis.

Operational definitions: explanation of how a researcher intends to measure a variable; may raise issues about validity and reliability of the experiment.

Replicated: a sign that research is reliable is if it is consistent.

Sample: known as a group of participants chosen for a research experiment.

Population: includes anyone or anything that could be selected to be in the sample; what the sample is chosen from.

Representative sample: a sample from a larger group that accurately represents the characteristics of a larger population.

Random sampling: when every member of a population has an equal chance of being selected to be in the sample.

Convenience sampling: when researchers collect data from a group of people who are easily accessible to them.

Generalize: an act of reasoning that involves drawing broad inferences from particular observations, is widely-acknowledged as a quality standard in quantitative research, but is more controversial in qualitative research.

Stratified sampling: process that allows the researcher to ensure that a sample represents the population on some criteria.

Confounding variables: any difference between experimental and control conditions that may affect the dependent variable.

Random assignment: process by which each participant has an equal chance of being placed in either group.

Experimenter bias: unconscious behavior of the researcher to favor the experimental group over the control group to increase the chance of their hypothesis being true.

Double-blind study: occurs when neither the participants or researcher impacts the outcome of the study.

Single-blind study: occurs when only participants don’t know which group they have been assigned.

Social desirability bias: the tendency to give answers that reflect well upon oneself.

Experimental group: the group in an experiment that receives the treatment operationalized in the independent variable.

Control group: the group in an experiment that serves as a basis for comparison; doesn’t receive the independent variable.

Placebo method: giving the control group and identical but harmless substance while giving the experimental group the drug being tested to accurately compare effects.

Placebo effect:

Positive correlation: when the presence of one thing predicts the presence of the other.

Negative correlation: when the presence of one thing predicts the absence of another.

Study: a qualitative method of research

Likert scales: Survey method that poses a statement and asks participants whether they agree or disagree with it.

Directionality problem: the inability to tell which of the variables came first in an experiment.

Third variable: an uncontrolled variable that can impact the outcome of the study.

Naturalistic observation: Observation of participants in an unobtrusive manner, often in their natural settings.

Structured interview: a way of interview that has fixed questions and a set structure.

Case study: a research method that gets detailed information about one participant or a small group of participants; cannot be generalized to a population.

Overview

• Hindsight Bias

  • After an event occurs, it’s easier to explain the phenomenon

  • Similar biases are confirmation bias and overconfidence

Hypotheses and Variables

• Hypothesis: Expresses a relationship between variables

• Variables: Things that vary over a research experiment

  • Ex. Religion, height, age, etc.

  • Independent: change in independent produces change in dependent

  • Dependent: the variable that is being measured or is changing

    • Example: Hypothesis states that watching violent television programs makes people more aggressive

      • Independent Variable: Television Programs shown to participants

      • Dependent Variable: Change in behavior

    • Variables need to be operationalized to show how researchers will measure them.

    • Raises many issues about the validity and reliability of the study

Validity and Reliability

• Research is valid when it measures what it is supposed to measure

• it is reliable when it can be replicated or is consistent

Sampling

• individuals that the study is being conducted on are the participants while the method of picking these people is sampling

  • Goal in sampling is to have a representative of a larger population

  • Random selection increases the likelihood that the sample represents the population

  • Stratified sampling ensures that the researcher has a sample that represents the population on some criteria

  • In other words, if 500 of the 1,000 students in a school are white, 300 are Black, and 200 are Latino, in a sample of 100 students I would want to have 50 white students, 30 Black students, and 20 Latino students. To that end, I could first divide the names of potential participants into each of the three racial groups, and then I could choose a random subsample of the desired size from each group.

Experimental Method

• field experiments have the advantage of being more realistic

• lab experiments are more controlled

Chapter 3: Statistics

Learning Objectives

In this chapter you will learn about:

• Descriptive statistics

• Correlations

• Inferential statistics

• APA Ethical Guidelines

Key Terms

• Central tendency

• Mean

• Median

• Mode

• Bimodal

• Positively skewed

• Negatively skewed

• Range

• Variance

• Standard deviation

• Normal curve

• Percentiles

• Correlation

• Correlation coefficient

• Scatterplot

• Statistically significant

• Effect size

• Replication

• Meta-analysis

• Peer review

• No coercion

• Informed consent

• Deception

• Informed assent

• Confidentiality

• Risk

• Protection from harm

• Debriefing

Overview

Content in this chapter is designed to help you understand and make inferences based on numerical data as indicated by the College Board for the AP Psychology test. Practice using statistical terms and processes to analyze data from psychological studies and to recognize valid conclusions.

Descriptive Statistics

Descriptive statistics summarize a set of data. For instance, a frequency distribution can show how many students have pets like dogs or cats. Graphing these findings can help visualize the data.

Measures of Central Tendency

• Mean: The average of all scores. Calculated by summing all scores and dividing by the number of scores.

• Median: The middle score when the data is ordered.

  • If odd number of scores: find the central one.

  • If even: average the two middle scores.

• Mode: The most frequently occurring score. A distribution can have no mode, one mode, or multiple modes (bimodal).

Skewness

• Distributions can be skewed (asymmetrical) due to outliers:

  • Positively skewed: More low scores, mean > median.

  • Negatively skewed: More high scores, mean < median.

Measures of Variability

• Range: Difference between the highest and lowest scores.

• Variance and Standard Deviation: Measures of how spread out scores are in relation to the mean.

Correlations

Correlations measure relationships between two variables both positively and negatively, from -1 (perfect negative) to +1 (perfect positive). A scatterplot graphically represents these correlations.

Inferential Statistics

Inferential statistics help determine if findings from a sample can be generalized to a larger population. This can involve tests like t-tests or ANOVAs, assessing the p-value to determine statistical significance. A p-value of 0.05 indicates significant results.

APA Ethical Guidelines

Ethical considerations in research are crucial:

• No coercion: Participation must be voluntary.

• Informed consent: Participants must be aware they are part of a study.

• Confidentiality: Participants' information must be protected.

• Risk: Participants should not experience significant harm.

• Debriefing: Participants should know the purpose of the study after its completion, especially in cases of deception.