Psychological Research

Valid

Is your data correct

Reliable

Will you consistently get the same results, no matter how frequently you conduct the test?

Falsifiable

Is there evidence that can prove our hypothesis incorrect? (hypothesis is not incorrect; a theory can be tested to see if it is incorrect)

Sample

A small group that is representative of the total population

Random sampling

When everyone in a group has an equal chance of being chosen for a study.

Stratified sample

Purposely choosing individuals that represent the various subgroups needed

Population

The complete group of individuals

Statistical Significance

The larger the sample size, the more statistically significant your results are considered to be (less likely that something is caused by chance)

Correlation

The relationship between two sets of data, or variables

Positive correlation

both variables will react in the same way (direct relationship)

Negative correlation

each variable reacts differently; as one variable increases, the other variable decreases (inverse relationship

Correlation is not….

Causation

Scatterplot

 straighter diagonal line = stronger correlation

Correlation coefficient

a number that shows the strength of the relationship between two sets of data or variables

0 —> 1

+

-1 —> 0

—

0

no correlation

Variables

Conditions or behaviors that are changing in experiments

Independent variable

condition or behavior that is changed in an experiment; placed on the x-axis

Dependent variable

condition or behavior that researchers think will be affected by the independent variable; placed on the y-axis

Meta- Analysis (Mary)

A technique that combines the results of multiple research studies into a single correlation or estimate

• Using previous, proven research studies

Negatives of meta- analysis

• No minimum number of studies or participants

• Information of interest could be missing from the original research that is being referenced

Positives of meta- analysis

• Combines data from multiple studies 

• Illustrates overall trends & patterns (helps us see the big picture–think Gestalt)

• Increases reliability of research (stronger evidence & more reliable conclusions since multiple studies)

• Identifies inconsistencies

Naturalistic observation (never)

Watching animals and people behave normally

• Used to form a hypothesis

• The subject can NOT know they are a part of an experiment or study

• Researchers should conceal themselves

Experiment (eats)

Used to determine cause and effect

• Used to prove/disprove a hypothesis

• Start with a hypothesis

• Looking for a relationship between variables

• Independent vs. dependent variables

  • Independent: what experimenters will change; applied to the experimental group

  • Dependent: what changes (if anything) because of the independent variable

• Participants must be randomly assigned and groups must be equal

Experimental group

the group to which experimenters will apply the independent variable

Control group

• group must be the same as the experimental group, except they are NOT given the experimental treatment

  • Often, they are given the placebo

Random sample

decides who will be in our research/study

Random assignment

 decides who from our sample will be in the experimental and control groups

Case- study (candy)

• Used to form a hypothesis

• Focuses on a particular disorder or experience

• Uses long-term observation, self-reports, diaries, and therapy session tapes

• Can’t prove anything about a population

  • Be careful not to overgeneralize

Correlational study (candy)

• Looking for a relationship between 2 variables (NOT causation)

• NO interference

Surveys

• Interviews, questionnaires, or a combination of the two

• Pros

  • Take less time

  • More uniform

• Cons

  • Social desirability bias

  • Response set (ie, checking “agree” without reading)

Longitudinal studies

• Studies and restudies the same group of people at regular intervals over a period of time

• Good for examining consistencies in behavior

Cross- sectional studies

• Organized groups of individuals based on AGE, that are randomly sampled

• Members of each group are surveyed, tested, or observed

Generalizable

means that results from a study can apply to a larger group, not just the people who were studied.