Lecture #2: Research Methods Flashcards
What is distribution
- Graphing variables
- Random sampling– ensure that the highest [variables] is in the middle and the least is on the extreme sides.
Central tendency
- Characteristic of distribution.
- Mean, median and mode.
Mean
- Average (e.g. Mean for IQ = 100).
- Affected by outliers (> 2 SD from the mean).
Median
- Middle value of a sequence.
- Used if there are many outliers.
Mode
- Most occurring data point.
- Least used
Standard Deviation
- Characteristic of distribution.
- Typical deviation (+/-) from the mean.
- Low SD = more [variable] around mean (lower is better: prob used random sampling).
- High SD = less [variable] concentration around the mean (higher is concerning: more non-random sampling). IQ SD = 15
Conceptual variable
- Conceptual variables are non-tangible things that are difficult to isolate and directly measure.
e. g. intelligence, happiness, sadness etc.
How do you study conceptual variables?
- Measure the behaviours that are associated with the conceptual variables.
- e.g. measure intelligence by looking at performance in university.
Operational definition
- A definition that states how a conceptual variable will measured.
Construct validity
- How well the operational definition is at measuring the conceptual variable.
- Low Concept validity = no relationship (scrap the operational definition).
- High concept validity = relationship between conceptual variable and operational definition).
What makes a useful test
- High construct validity (must be high—have a relationship)
- Test-retest reliability: (consistent results when completed multiple times).
- Inter-rater reliability: (consistent results with different administrators).
- Descriptive research
- First type of research approach.
- Observations
- Cannot infer causation as there is no manipulation of the IV.
- Case studies, surveys and naturalistic observations.
Case study
- Examining exceptional examples of an individual.
- Give proof of existence.
- Doesn’t always apply to the rest of the pop’n (rare cases).
- Example of descriptive research (cannot infer causality). - Phineas Gage.
Surveys
- Generalized questionnaires
Limitations:
- Problems of self assessment: lying, positive impression management (exaggerating positive traits), malingering (exaggerating problems) and wording of questions could give inaccurate results.
Naturalistic observations
- Collecting data by observing
- High external validity (still valid outside lab–as already out of lab).
- No intervention (no problems with self-assessment).
- No negative observer effects.
Limitations:
- Cannot be controlled
- Limited variables difficult to study (infrequent behaviours)
e. g. in the subway.
- Correlational analysis
- Type of research approach.
- Measuring relationships between data.
- Negative correlation, no correlation, positive correlation.
Pearson r: (0-1) - Lower “r” value = weaker correlation.
- Higher “r” value = stronger correlation
- ”+/-“ (“+” = upward trend & “-“ = downward trend).
Interpreting correlation
- Correlation does not mean causation (just suggest causation).
- May be a 3rd factor, spurious association (ridiculous correlations) or there may be a relationship but no correlation (non-linearity or U-shaped–making r-value = 0).
- True Experimental research
- Type of research approach.
- Way to determine causality.
- Manipulate Independent variable (IV) and measure the Dependent variable (DV).
- Keep all variables constant except the IV to accurately determine causality.
- Include a control group.
- Randomly assign people.
Quasi experiment
- Don’t randomly assign people.
- Not a true experiment.
Between-subject design
- 2 + groups are given a different treatment.
- Cheaper
Within-subject design
- One subject group is studies 2 + times.
- Good for experiments involving time.
- Control for confounding variables
- Loss of subjects
Mixed
- 2 + groups studies 2 + times.
- Control for confounding variables.
- More expensive and take longer
- Loss of subjects.
Sampling
- Concern with experiment design
- External validity: make sure that the lab conditions match the conditions in the pop’n.
- E.g. W.E.I.R.D. oversampling (western, educated, industrialized, rich and democratic).
Confounding variables
- Concern with experimental design.
- Variables that are not controlled (affecting the DV and/or IV).
Demand characteristics
- Concern with experimental design
- Giving clues to subjects (allows for subjects to modify their behaviour)
- So, deceive subjects (although inform of risk).
Observer/Hawthorn effect
- Subjects trying more as they know they are being watched.
Placebo
- Counters pre-existing expectation about treatment (that can alter behaviour).
- If treatment works: the drug must work more than the placebo group and the control group.
Experimenter effect
- Unconsciously affect experiments when they want certain results.
- Solution: double-blind (experimenters and subjects both don’t know which group the subjects are in.