Unit 0 - Need for Psychological Science, Research Methods, and Data Interpretation

What is psychology?

The scientific study of the brain and its behavior and how it affects human mental process

What are four main goals in psychology?

Describe, explain, predict, and change

How do we accomplish describing, explaining, predicting, and changing?

Empirical evidence

Definition of empirical evidence

Psychologist rely on observable and measurable data. They conduct experiments, surveys, and case studies.

Definition of hindsight bias

A person thinking they knew it all along

Definition of overconfidence

Overestimating knowledge

Definition of perceiving order in random events

Making a pattern out of real random events

Definition of confirmation bias

Pre-existing belief or opinion, always looking for things to prove them right

Theory

A prediction you make after observing something with a structured explanation

Hypothesis

A specific testable prediction derived from a theory

Operational definition

Defining a concept in terms of how you plan to measure that concept

Replication

Testing reliability

Peer reviewers

The gatekeepers of quality maintains integrity and accuracy of the study

Case study - Non-experimental

In depth, analysis of one or a small group

Correlation study - Non-experimental

Examining relationships between two or more variables, not causation

Meta-analysis - Non-experimental

Combining previous study results on the same topic

Natural Observation - Non-experimental

Watching behavior in natural environment

Survey

Gathering data from questionnaires or interviews to collect data

Population

The whole group

Sample

Small portion of the whole

Sampling technique - Random

Equal chance

Sampling technique - Convenience

Easy but risky

social desirability bias - non-experimental

Answering a certain way to look good

Self-report bias - Non-experimental

Answering with flawed memories

Experimental bias - non-experimental

Researcher influence outcomes of participants answer

Correlation definition

Non-experimental relationship

Positive correlation

As one variable increases, the other also increases, (same direction)

Negative correlation

One variable increases while the other decreases, (opposite directions)

Correlation is not…

Causation

Correlation coefficient

numerical value that represents the strength and direction of a correlation

Scatter plot

A graphical representation of the relationship between two variables

Illusory Correlation

When you think you see a correlation, but there’s no relationship between two variables

Regression to the mean

This is the tendency for extreme or unusual scores to fall back toward the average

Independent variable

The variable that is being manipulated by the experimenter

Dependent variable

The variable that is measured to see how it is affected by changes in the independent variable

Confounding variable

An external factor that could influence the results of the experiment

Experiment group

A group in an experiment that receives the treatment or manipulation

Random sample

A random sampling to decrease bias and give everyone an equal chance

Placebo

A harmless, inactive, substance or treatment given to the control group to compare its effects with those of the actual Treatment

Control group

A group and an experiment that does not receive the treatment allowing comparison

Random assignment

Participants are randomly assigned to the experimental or control group to ensure that each group is similar to the reaction

Single blind experiments

Participants do not know whether they are in the experiment or control group

Placebo effect

The phenomenon where participants experience changes simply because they believe they are on the treatment

Double blind

Both the participants and the person studying them don’t know which group is getting the drug

Qualitative

A study done in detail, small portion, and good quality

Quantitive

A study done in big portion, not a lot of detail, and lots of numbers for data (generalizing)

Descriptive stats

Summarize and describes quantitative info, and explains known data

Inferential stats

Predict and generalize to larger portions and attempts to reach a conclusion

Mean (average)

Sums up all of the scores

Median

The middle number of all the data

Mode

Scored most often in the data set

Range

Biggest number to smallest number

Standard deviation

The average distance of each score from the mean, The closer together, the more reliable the data

Bell curve

Mean, median, and mode are all equal and located at the center of the curve

Skewness

A measure of the asymmetrical of a distribution

Percentile rank

The percentage of scores that are lower than given score

Inferential statistics

Numerical data that allows one to generalize/to infer from sample data that probability of something being true of a population

statistical significance

A statistical statement of how likely it is, that a result occurred by chance, assuming there is no difference between the population being studied