1. Quantitative Research Methods

2. Types of Psychological Research
Quantitative Research
Analyzes results using numbers
Ignores the context of a person
Qualitative Research
Only uses numbers (frequencies, percentages) to generate themes
Focus is on context

3. Types of Quantitative Research Methods
Experiments
Correlational Studies
Surveys

4. Characteristics of all Quantitative Research Methods
Narrow and focused
Objective
Meant to be artificial
Structured and controlled
Not meant to show the context of life
Low in reflexivity (researcher does not reflect on how s/he might influence results)

5. Characteristics of Experiments (Schumacher & McMillan, 1984)
Compares at least 2 groups or 2 conditions to show causation
Uses at least one independent variable (IV)
Measures at least one dependent variable (DV)
Uses inferential statistics to determine statistical significance

6. Experimental Variables
Independent Variable (IV)
is the variable being manipulated and controlled by the experimenter so that the effect can be measured. (Cause)
Dependent Variable (DV)
is the behavior to be measured that is “dependent” on the independent variable. (Effect)
Both variables need to be operationalized

7. Types of Experimental Design
Independent Samples (Between Group Designs) Some subjects are only exposed to part of the independent variable. Utilizes control groups.
Repeated Measures (Within Group Designs) All subjects are exposed to all parts of the independent variable

8. Independent Samples/Between Groups
Recruit a group of participants
Divide them into two random groups
Group Group 2
This group does the experimental task with the IV set for condition 1
This group does the experimental task with the IV set for condition 2
Measure the DV for each group
Compare the results for the two groups

9. Repeated Measures/Within Groups
Recruit a group of participants
Condition Condition 2
(Memorize words (Memorize words
without music) with music)
The group does the experimental task with the IV set for condition 1
The group repeats the experimental task with the IV set for condition 2
Compare the before/after results for the two conditions

10. Recruiting Participants (Sampling Techniques)
Non-representative Samples Typically Used
* Convenience (Opportunity) Samples
Self-selected Samples ($$)
Notes
Results only generalizable to the individuals studied
Random allocation (to groups or treatments) essential

11. Strengths of Experiments
Control is the greatest strength
Only research method to show cause and effect

12. Weaknesses of Experiments
Poor control (of confounding variables) is greatest weakness
Ethics (potential harm, deception etc) can be a problem
Experimenter bias can occur
Low ecological validity is NOT a weakness if triangulation is used

13. Characteristics of Correlational Studies
They show positive/negative relationships between 2 variables
They can be useful when ethics are a concern (smoking risks)
They typically use questionnaires (as opposed to surveys)
They NEVER show causation

14. Characteristics of Questionnaires
Questionnaires gather data about human characteristics (Neuman, 2006)
They have a limited focus investigating topics such as:
One’s behavior (ie, whether you voted)
Attitudes/beliefs/opinions (ie, bullying)
Certain characteristics (ie, marital status)
Expectations (ie, future of your children)
Frequencies (ie, number of stressful events)

15. Correlation Coefficients (r)
Ranges from -1.0 to 1.0
No Relationship .00 to .09
Weak Relationship
.10 to .29 (Popov et al, 2017)
.10 to .39 (Jamison, 2017)

16. Correlation Coefficients (r)
Ranges from -1.0 to 1.0
Moderate Relationship .30 to .49 (Popov et al, 2017)
.40 to .79 (Jamison, 2017)
Strong Relationship
.50 to 1.0 (Popov et al, 2017)
.80 to 1.0 (Jamison, 2017)

17. Strengths of Correlational Studies
Can be used in place of unethical experiments (ie, does increasing the time spent on social media increase depression?)
Helps to determine relationships between 2 variables
If correlations are strong, useful predictions can be made

18. Weaknesses of Correlational Studies
Causation can never be established despite the number of replications
Pathway for the correlation is hard to know (ie, do violent TV shows bring-out violence in people or do violent people watch violent TV shows?)

19. Characteristics of Surveys
Designed to generalize results to a larger target population
Contain a broad range of goals
Uses representative samples (Simple Random Samples, Stratified Random Samples)
Results reported with percentages or correlations

20. Strengths of Surveys Many objectives can be studied at the same time
Results can be generalized to a larger (target) population through random samples

21. Weaknesses of Surveys
Not always certain if survey was completed by the randomly selected participant
People lie
Questions can be biased or confusing