Unit 0 Scientific Foundations of Psychology

hindsight bias

the tendency to believe, after learning an outcome, that one would have foreseen it. (Also known as the I-knew-it-all-along phenomenon.) (Myers Psychology 10e CH01 p. 18)

critical thinking

thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions. (Myers Psychology 10e CH01 p. 23)

theory

an explanation using an integrated set of principles that organizes observations and predicts behaviors or events. (Myers Psychology 10e CH01 p. 24)

hypothesis

a testable prediction, often implied by a theory. (Myers Psychology 10e CH01 p. 24)

operational definition

a statement of the procedures (operations) used to define research variables. For example, human intelligence may be operationally defined as what an intelligence test measures. (Myers Psychology 10e CH01 p. 25)

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. (Myers Psychology 10e CH01 p. 25)

case study

an observation technique in which one person is studied in depth in the hope of revealing universal principles. (Myers Psychology 10e CH01 p. 25)

naturalistic observation

observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation. (Myers Psychology 10e CH01 p. 26)

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. (Myers Psychology 10e CH01 p. 28)

population

all the cases in a group being studied, from which samples may be drawn. (Note: Except for national studies, this does not refer to a country's whole population.) (Myers Psychology 10e CH01 p. 29)

random sample

a sample that fairly represents a population because each member has an equal chance of inclusion. (Myers Psychology 10e CH01 p. 29)

correlation

a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other. (Myers Psychology 10e CH01 p. 29)

correlation coefficient

a statistical index of the relationship between two things (from -1 to +1). (Myers Psychology 10e CH01 p. 29)

scatterplots

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. The amount of scatter suggests the strength of the correlation (little scatter indicates high correlation). (Myers Psychology 10e CH01 p. 29)

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. (Myers Psychology 10e CH01 p. 32)

experimental group

in an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable. (Myers Psychology 10e CH01 p. 33)

control group

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. (Myers Psychology 10e CH01 p. 33)

random assignment

assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between those assigned to the different groups. (Myers Psychology 10e CH01 p. 33)

double-blind procedure

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 a placebo. Commonly used in drug-evaluation studies. (Myers Psychology 10e CH01 p. 33)

placebo effect

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. (Myers Psychology 10e CH01 p. 33)

independent variable

the experimental factor that is manipulated; the variable whose effect is being studied. (Myers Psychology 10e CH01 p. 34)

confounding variables

a factor other than the independent variable that might produce an effect in an experiment. (Myers Psychology 10e CH01 p. 34)

dependent variable

the outcome factor; the variable that may change in response to manipulations of the independent variable. (Myers Psychology 10e CH01 p. 34)

mode

the most frequently occurring score(s) in a distribution. (Myers Psychology 10e CH01 p. 36)

mean

the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores. (Myers Psychology 10e CH01 p. 36)

median

the middle score in a distribution; half the scores are above it and half are below it. (Myers Psychology 10e CH01 p. 36)

range

the difference between the highest and lowest scores in a distribution. (Myers Psychology 10e CH01 p. 38)

standard deviation

a computed measure of how much scores vary around the mean score. (Myers Psychology 10e CH01 p. 38)

normal curve (normal distribution)

a symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean (about 68 percent fall within one standard deviation of it) and fewer and fewer near the extremes. (Myers Psychology 10e CH01 p. 38)

statistical significance

a statistical statement of how likely it is that an obtained result occurred by chance. (Myers Psychology 10e CH01 p. 40)

Confirmation Bias

the tendency to search for, interpret, and remember information in a way that confirms one's preexisting beliefs or hypotheses.

Overconfidence

the tendency to overestimate the accuracy of one's beliefs, knowledge, or judgments.

Psychology

the scientific study of behavior and mental processes.

Peer review

the process by which scholars evaluate each other's work before publication to ensure quality and validity.

Falsifiable

capable of being tested and potentially proven false through observation or experimentation.

Social desirability bias

the tendency of individuals to respond to questions in a manner that will be viewed favorably by others, often leading to inaccurate self-reports.

Experimenter bias

a cognitive bias that occurs when a researcher's expectations or preferences influence the outcome of an experiment.

Sample

a subset of a population used in research to draw conclusions about the larger group.

Sampling bias

a type of error that occurs when the sample selected for a study is not representative of the population intended to be analyzed.

Convenience Sampling

a non-probability sampling technique where participants are selected based on their easy availability and proximity to the researcher.

Representative sample

a subset of a population that accurately reflects the members of the entire group, ensuring that key characteristics are proportionately represented.

Meta-analysis

a statistical technique that combines the results of multiple studies to identify patterns, relationships, or overall effects.

Self-report bias

a type of bias that occurs when participants provide inaccurate or untruthful responses in surveys or questionnaires, often due to social desirability or lack of self-awareness.

Experiment

a research method in which an investigator manipulates one or more variables to observe the effect on a dependent variable, while controlling for confounding or outside factors.

Correlation

a statistical measure that describes the extent to which two variables change together, indicating the strength and direction of their relationship.

Directionality Problem

a limitation in correlational research that arises when it is unclear which variable influences the other, making it difficult to determine causation.

Third Variable Problem

a situation in correlation research where a third variable may be influencing both of the variables being studied, potentially misleading the interpretation of their relationship.

Regression toward the Mean

the phenomenon where extreme or unusual observations tend to be followed by more typical or average ones, reducing the effect of outliers in data.

Single blind

a research design in which only the participants are unaware of whether they are in the experimental or control group, helping to reduce bias in their responses.

Informed consent

the process by which participants are fully informed about the nature of the research, including any risks and benefits, and voluntarily agree to participate.

Protection from Harm

a principle in research ethics that ensures participants are not exposed to physical or psychological harm during the study.

Informed assent

a process similar to informed consent, where individuals who are not legally able to give consent (such as minors) are provided with information about the research and give their agreement to participate.

Confidentiality

the ethical principle that ensures participants' personal information is kept private and not disclosed without their consent.

Debriefing

the process of informing participants about the study's purpose and any deception that occurred after their participation.

Quantitative Research

a method of inquiry that focuses on quantifying relationships, behaviors, or phenomena through statistical analysis and measurable variables.

Qualitative Research

a method of inquiry that emphasizes understanding human behavior and experiences through non-numerical data, such as interviews and observations.

Likert Scale

a psychometric scale commonly used in surveys to measure attitudes or opinions by asking respondents to specify their level of agreement with a statement.

Institutional Review Board (IRB)

a committee that reviews research proposals to ensure ethical standards are met, protecting the rights and welfare of human subjects involved in research.

Research Confederates

individuals who are part of a study but act as if they are participants, helping researchers observe behaviors and interactions in a controlled setting.

Percentile Rank

a statistical measure indicating the relative standing of a score within a group, showing the percentage of scores that fall below it.

Skewed Distribution

a statistical distribution that is not symmetrical, where one tail is longer or fatter than the other, indicating a bias in the data.

Bimodal Distribution

a statistical distribution with two different modes or peaks, indicating that there are two prevalent values in the data set.

P-value

a measure that helps determine the significance of results in hypothesis testing, indicating the probability of obtaining the observed results under the null hypothesis.

Effect size

a quantitative measure of the magnitude of a phenomenon, often used to assess the strength of a relationship in statistical analysis.