Psych research methods and data interpretation

Random Sampling

allows for a sample size that represents more of the population

Sampling Bias

when the sampling in the study does not represent the larger population accurately, which can lead to misleading conclusions.

Convenience Sample

when participants are selected based on their easy accessibility to the researcher, rather than being chosen randomly. Method is convenient, but can introduce biases, as it may not represent a broad population.

Case Study

Research method where there is an in-depth analysis of a single individual, or small group of individuals, typically focusing on a rare or unique case.

Naturalistic Observation

Research method where the researcher observes and records behavior in a natural setting without interfering with or manipulating the situation.

Correlational Research

Research method which examines the relationship between variables showing how changes in one factor predicts changes in another. All of this is done without any manipulation of the variables. 

Meta Analysis

Research method that looks at data from a number of independent studies of the same subject, in order to determine overall trends. 

Expierment

Research method in which an experimenter can determine cause and effect through the manipulation of the independent variable. 

Correlational studies 

relationship between two or more variables, measure without manipulating them to see if they affect one another. 

Correlational Coefficient (r-value)

stronger = 1/-1, weaker =0

correlation does not imply causation

only experiments can prove cause and effect

Directionality Problem

Occurs when it is unclear which variable causes the other.

Cross sectional study

sample collected from a population at one given time.

Longitudinal study

Sample collected from the same population over a prolonged period of time. 

Hypothesis

A prediction, should be falsifiable

Falsifiability

Something that can be tested and potentially proven false.

Independent Variable

The variable which is manipulated by the researcher

Dependent Variable

Whats being measured in an experiment

Reliability

ability to be replicated

Validity

Did the researcher measure what they wanted to?

Confounding Variable

Unaccounted for factor whose presence effects the variables being studied so that the results yo get do not reflect the actual relationship in the study. 

Control Group

Group given a control, or a “placebo“

Experimental Group

Group given the “treatment“

Placebo

Whats given to the control group to see if the the treatment works on the experimental group

Placebo Effect

When the participants behavior improves due to them thinking their placebo worked.

Random Assignment

Allows a researcher to control for possible confounding variables.

Allows for comparison

Random Sampling

Allows for Generalization

Peer Review

The process of submitting a researchers findings for evaluations by experts in the same field.

Survey

Technique used for obtaining the self-reported attitudes or behaviors of a particular group. (Likert scale)

Quantitative 

Numerical

Qualitative 

words

Regression toward the mean

In any situation where chance plays a role, extreme outcomes are likely to be followed by results that are closer to the mean.

-occurs when more data is collected (think coin lab)

Descriptive Statistics

To summarize or describe the main features of a data set

Inferential Statistics

Before you can infer/generalize your data to the larger population, you need to be sure that your findings are not just accidental, and did not occur by luck.

Statistical Significance

The results of a study did not likely occur by chance.

The closer the P value is to 0, the more statistically significant the data is

Effect Size

Magnitude of the difference between groups.

Larger effect size = more practical significance

Cohens D

Small effect size: D=0.2

Medium effect size: D=0.5

Large effect size: D=0.8

-The less the curves overlap, the greater the effect size

Ethical Guidelines

-Informed consent / informed assent

-Protect participants from harm

-confidentiality

-Deception is okay as long as a debrief occurs 

Confirmation Bias

The tendency for a person to look for information that supports their beliefs, while ignoring the evidence that does not.  

Hindsight Bias

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

Overconfidence

The tendency to overestimate how accurateyou are.

Histogram

a graph where the bars touch