Module 0 Psychology

Basic v. Applied Research

Basic Research: Research designed to increase psychological knowledge and develop theories; without necessarily solving an immediate practical problem

Applied Research: Research that tales psychological knowledge and uses it to address practical, real-life problems

Scientific Attitude

Curiosity: A desire to investigate, ask questions, and discover how or why something occurs

Skepticism: Not accepting claims immediately and instead looking for evidence before deciding they are true

Humility: Understanding that beliefs can be incorrect and being willing to revise them when evidence shows otherwise

Critical Thinking

Carefully analyzing information by questioning assumptions, checking the credibility of sources, identifying possible biases, examining evidence, and judging whether conclusions are reasonable

Hindsight Bias

The tendency to believe, after something happens, that the outcome was predictable or obvious from beginning—often called the “I knew it all along” effect

Overconfidence

Being more confident in one’s knowledge, judgements, or predictions than is justified. Repeating studies can help determine whether conclusions are actually dependable

Order in Random Events

The tendency to see meaningful patterns in information that is actually random. This is related to illusory correlation, where people incorrectly believe two things are connected

Scientific Method

Peer Review

Other experts examine a study to evaluate its methods, evidence, and conclusions

Theory

A broad explanation that organizes observations and helps predict behavior or events. Ex: eating a nutritious breakfast may improve academic performance

Hypothesis

A specific prediction that can be scientifially tested

Falsifiable

A claim that can be tested and could potentially be shown to be incorrect

Null Hypothesis

A prediction stating that there is no significant relationship or difference between variables

Operational Definition

A precise description of exactly how a variable will be measured or manipulated in a study

Replication

Repeating a study using similar procedures to determine whether similar results occur again. Repeating research to determine whether the original findings can be reproduced. Successful replication increases confidence that the findings are reliable and were not simply caused by chance

Psychological Science

• Describe behavior and mental processes

• Explain why behaviors occur

• Predict how people may behave or think

• Influence/control behavior and mental processes

Case Study

A detailed investigation of one individual or a small group. It provides extensive information but may not apply to the larger population

Patient H.M.

Henry Molaison was a famous case study whose brain surgery caused severe problems forming new memories. His case helped psychologists unde

Naturalistic Observation

Watching and recording behavior in a person’s or animal’s normal environment without interfering. it shows realistic behavior but gives researchers less control over outside variables

Survey

A research method that collects people’s self-reported attitudes, opinions, or behaviors through questions. Results can be affected by wording effects or social desirability bias, when people answer in ways they believe are more acceptable

Wording Effects

The way a question is written or asked can influence how someone responds. This may create bias and make survey results less accurate. Ex. You still think the robber was 5’8”

Social Desirability Bias

When participants give answers they believe will make them appear better or more socially acceptable instead of answering truthfully. This can make self-reported information less accurate.

Self-Report Bias

Errors that occur when people provide inaccurate information about themselves because of poor memory, exaggeration, or dishonesty. This can decrease the validity of survey and interviews. Report their behavior inaccurately. Ex. A person is taking a survey on sexual practices; one of the question say in the past month, how many sexual partners did you have. That person will mark the number they feel comfortable sharing

Random Sampling

A method where every person in a population has an equal opportunity to be selected. It helps create a more representative sample and improves the ability to generalize the results

Sample

A smaller group selected from a larger population to participate in a study. If the sample does not accurately represent the population, the results may not apply to the entire group. Representative group of the population

Sampling Bias

When the selected sample does not properly represnt the population being studied. This makes it more diffcult to generalize the study’s findings

Random Sample

A group of participants selected entirely by chance, giving each member of the population an equal chance of being included. This helps reduce selection bias. A larger group is more efficient than a smaller sampling group

Stratified Sampling

A sampling technique that makes sure important subgroups within a population are properly represented. For example, a researcher might include proportional numbers of freshmen, sophomores, juniors, and seniors

Population

The complete group that researchers want to study and draw conclusions about. A sample is selected from this larger group

Correlation

Describes the relationship between two variables and how they change together. Correlation does not prove causation. Correlations are often displayed using scatterplots and measured with correlation coefficients

Correlation Coefficient

A number ranging from -1.00 to +1.00 that indicates the direction and strength of a relationship between two variables. Values closer to -1 or +1 indicate stronger relationships, while values near 0 indicate weaker relationships

Variable

Any factor or characteristic that can be measured and can change within a study. Examples include independent, dependent, and confounding variables

Positive Correlation

A relationship where two variables move in the same direction. As one increases, the other tends to increase. Ex. More studying is associated with higher test scores.

Negative Correlation

A relationship where two variables move in opposite directions. As one increases, the other tends to decrease. Ex. As hours of sleep decrease, stress levels increase. Also called inverse relationship

Scatterplot

A graph made of plotted points that shows the relationship between two variables. The pattern of the points helps show the direction and strength of the correlation

Line of Best Fit

A line drawn through a scatterplot that best represents the overall pattern of the data. It can be used to make predictions about one variable based on another

Illusory Correlation

The false belief that two variables are related when no real relationship exists. This can contribute to superstitions and stereotypes. Ex. Athletes with their lucky socks. Correlation does not prove causation; one thing does not necessarily cause another

Regression Toward the Mean

The tendency for unusually high or low results to become closer to the average when measured again. Researchers must be careful not to mistake this natural change for the effect of a treatment or intervention. Tendency for things to go back to the average

Experiment

A controlled research method used to determine cause and effect relationships. Researchers manipulate one variable and observe its effect on another. Experiments are the main method for establsihing causation

Experimental Group

The group that receives the treatment or is exposed to the independent variable. Its results are compared with the control group

Control Group

The group that does not receive the experimental treatment and serves as a comparison. It helps researchers determine whether changes were actually caused by the treatment

Assignment and Random Assignment

Placing participants into experimental or control groups by chance. This helps make the groups similar and reduces the influence of confounding variables

Group Matching

Creating groups that are similar in important characteristics, such as age, gender, or ability. This helps reduce differences between groups that could affect the results

Procedures

steps followed during a research study

Single Blind and Subject Bias

Participants do not know whether they are in the experimental group or control group. This helps prevent their expectations from influencing their behavior or responses. Helps against subject bias.

Hawthorne Effect

When participants change their behavior simply because they know they are being watched or studied. This can affect the accuracy of experimental results

Double-Blind Procedure

Neither the participants nor the researchers interacting with them know who is receiving the real treatment or the placebo. Usually the lead researcher knows the procedure. Prevents both single-subject bias and experimenter bias

Placebo and the Placebo Effect

A placebo is an inactive or fake treatment. The placebo effect occurs when someone experiences a change because they expect the treatment to work, even though the treatment itself has no active effect

Counterbalancing

Changing the order in which participants experience different conditions in a repeated-measures study. This helps control order effects, such as improvement from practice or worse peformance from fatigue

Independent Variable

the factor being manipulated, tested for its effect on the dependent variable. Variable the investigator manipulates

Dependent Variable

The measured outcome. Changes in this variable illustrate whether the hypothesis is supported or denied

Experimenter Bias

Researcher unintentionally influences results. Double-blind procedures help reduce this bias

Confounding variable

An outside factor that could influence results. Confounds threaten the validity and reliability of experiments

Validity v. Reliability

Validity is the accuracy of the results and reliability is the consistency of the results. Both of these are necessary for a credible experiment

Longitudinal Study

A research method that studies the same group of people over a long period of time to observe changes. It can provide reliable information about development over time, but participants may drop out of the study

Cross-Sectional Study

A research method that compares different groups of people at the same point in time. It is quicker than a longitudinal study, but it is less effective at showing how individuals change over time

Quantitative Research

research that collects and analyzes numerical or measurable data such as data from surveys or rating scales

Qualitative Research

gathers detailed, descriptive information rather than numerical data. An example is strcuctured interview

Likert Scale v Interviews

Likert scales collect quantitative data by measuring attitudes or opinions using numerical ratings. Structured interviews collect qualitative data through detailed responses that can help researchers better understand why a person thinks or behaves a certain way

Research Ethics

Rules and standards designed to make sure research is conducted safely, fairly, and responsibly. The Institutional Review Board (IRB) reviews research involving human participants, while ethical standards also apply to animal research. In the United States, the American Psychological Association (APA) provides ethical guidelines for psychological research involving both humans and animals

Animal Research

Clear and specific purpose must care for and humanely house the animals; must acquire the animals legally and humanely; and must design procedures that employ the least amount of suffering feasible

Human Research

• Informed consent

• Has to be voluntary

• Anonymity/confidentiality

  • Patient H.M. is Henry Molison

• Debriefing- the subject being told the purpose of the experiment afterward

IRB

Institutional Review Board; reviews research proposals for ethical violations or inaccuracies

Type I Error

reject a null hypothesis. Concluding an effect exists when it does not

Type II Error

Accept the null hypothesis. Failing to detect an effect that exists

Descriptive Statistics

numerical methods used to organize, summarize, and describe the characteristics of a set of data. They are often displayed using graphs, histograms, or frequency distributions

Histogram

A graph that shows how often scores fall within different ranges or intervals. It helps show the overall shape and distribution of the data

Measures of Central Tendency

Statistics used to identify the center or typical value of a data set. The three main measures are mean, median, and mode, and each is affected differently by extreme scores

Mode

The value that appears most frequently

Bimodal

a distribution that has two values or groups that occur most frequently. Having two peaks can make a single measure such as the mean less representative of the overall data

Mean

the average of all scores, calculated by adding the scores and dividing by the number of scores. The mean is strongly affected by extreme scores or outliers

Median

The middle score when all scores are arranged from lowest to highest

Extreme scores

Unusually high or low scores, also called outliers. They can significantly change the mean and ca increase measures of variation such as the standard deviation

Measures of Variation

statistics that describe how spread out or diverse the scores are. Examples include the range, variance, and standard deviation

Range

The difference between the highest and lowest scores in a data set. It is a simple way of measuring variation but does not show how either scores are distributed

Standard Deviation

A measure of how much scores are typically differ from the mean. A small standard deviation means scores are clustered close to the mean, with a large standard deviation means scores are more spread out

Z Score

A statistical value that shows how many standard deviations a particular score is above or below the mean. A positive z-score is above the mean, while a negative z-score is below it

Normal Curve/Distribution

a symmetrical, bell-shaped distribution in which most scores are located near the mean and fewer scores appear toward the extremes

Positively Skewed

A distribution with a long tail extending toward the higher scores. There are usually more low scores, and extremely high scores pull the mean upward. Therefore, mean>median.

Negatively Skewed

A distribution with a long tail extending toward the lower scores. There are usually more high scores and extremely low scores pull the mean downward. Therefore, mean < median

Variance

a measure of how spread out scores are around the mean. Variance is the standard deviation squared. To find the standard deviation from the variance, take the square root

Inferential Statistics

Numerical data that allows one to generalize their findings

Statistical Significance

mathematical measure that tells you if an experimental result or data pattern is likely real or just a fluke caused by random chance

Effect Size

Measures the strength or size of a relationship or difference found in a study. It helps show how meaningful the results are, beyond whether they are statistically significant

P-Value

the probability, assuming the null hypothesis is true, of obtaining results at least as extreme as those observed. A p-value below 0.05 is commonly considered statistically significant, leading researchers to reject the null hypothesis. A p-value above 0.05 means there is not enough evidence to reject the null hypothesis

Meta-Analysis

A meta-analysis is a research method that combines the results of many different studies on the same topic to find an overall conclusion

Ex: Researchers combine 30 studies about whether exercise reduce stress to see the overall effect