4.2.3 - Research Methods Flashcards
Define aim?
A general statement of what the researcher intends to investigate
Define hypothesis?
A clear, precise, testable statement of what the researcher believes to be true
Give an aim about how sweets relate to health?
To investigate how sweets impact a person’s health
Give a non-directional hypothesis for how sweets relate to health?
There will be a difference between the life expectancy of someone who eats more than 3 bags of sweets a week, compared to someone who eats less than 3 bags of sweets a week
Give a directional hypothesis for how sweets relate to health?
A person who eats more than 3 bags of sweets a week will have a lower life expectancy than a person who eats less than 3 bags of sweets a week
Give three characteristics of a hypothesis
- Clear
- Makes a PREDICTION
- Testable
What are the terms for a hypothesis made about there being a difference when the IV is changed?
- Alternative
- Experimental
- Research
What is the term for a hypothesis that states there will be no difference when the IV is changed?
Null hypothesis
What must you do regarding the hypotheses after the experiment?
State whether alternative/experimental/research or null was right
Define directional hypothesis?
Hypothesis that states the sort of difference anticipated between two groups/ conditions
(1 tailed)
Define non-directional hypothesis?
A hypothesis that states there is a difference between two groups/ conditions, but doesn’t state what the difference will be
(2 tailed)
When would you use a directional hypothesis?
When previous studies suggest a certain outcome
When would you use a non-directional hypothesis?
When there are no/ no conclusive previous studies
Define experimental method?
Manipulating an independent variable to measure affect on a dependent variable
Define independent variable (IV)?
The variable that is manipulated or controlled by the researcher.
Define dependent variable (DV)?
The variable that is measured to show the affect of the IV.
Define operationalisation?
Clearly defining variables (in a hypothesis) in terms of how they can be measured
Name and define the two types of experimental conditions?
- Control group/condition (doesn’t experience change of independent variable, acting as a baseline for comparison)
- Experimental group/condition (experiences change of independent variable)
Define extraneous variables?
Nuisance variables that do not vary with the IV but may have the potential to affect the DV, so some may be controlled by the researcher.
Define confounding variables?
Variables that vary systematically with the IV, so will alter the DV and must be controlled by the researcher.
When a variable HAS AFFECTED the DV it is said to have ‘confounded’ the results
Name 4 types of control in experiments?
- Randomisation (v)
- Standardisation (v)
- Random allocation (p)
- Counterbalancing (p)
Define demand characteristics?
Any cue from the researcher/research situation that may reveal the purpose of the study and cause participants to alter their behaviour accordingly
Define investigator effects?
Any effects of the investigator’s unconscious/conscious behaviour on the DV
Define randomisation?
Use of chance when designing experiments to reduce the likelihood of bias
Define standardisation?
Using the exact same formalised procedures and instructions for all participants of the study to reduce bias
Define single blind trial?
Participant doesn’t know purpose of study (reduces demand characteristics)
Define double blind trial?
Participant and investigator don’t know purpose of the study (reduces chances of demand characteristics + investigator effects)
Define random allocation?
Randomly allocating participants to each experimental condition (equal chance to get picked for each condition)
- Reduces chance of individual differences in independent groups method
Define counterbalancing?
Changing order that participants experience conditions (ABBA)
- Reduces chance of order effects for repeated measures method
Define order effects?
Effects that arise when participants experience more than 1 condition.
- May cause better 2nd performance due to practice
- May cause worse 2nd performance due to fatigue/ boredom
(Can be reduced using counterbalancing)
Define experimental design?
Way in which participants can be organised in relation to experimental conditions
Name 3 forms of experimental design?
- Independent groups
- Repeated measures
- Matched pairs
Define independent groups method?
Participants are split into two groups, where each group experiences one condition
Benefits of independent groups method?
- No order effects
- Less likely demand characteristics
Problems with independent groups method?
- More participants (expensive)
- Participants have individual differences (can be CV, reducing validity)
Define repeated measures method?
Same participants take part in all conditions
Benefits of repeated measures method?
- No participant differences (controls CV)
- Less participants (cheaper)
Problems with repeated measures method?
- Can be order effects
- Can be demand characteristics
Define matched pairs method?
Participants are paired based on variable(s) that may affect the DV and one is assigned to each group/ condition
Benefits of matched pairs method?
- Fewer individual differences of participants (reduces CV, more valid)
- Less likely demand characteristics
- No order effects
Problems with the matched pairs method?
- Still some individual differences (can’t control all CVs)
- Matching is time consuming + expensive
- More participants
What is validity?
How true/ legitimate something is
What is internal validity?
Extent to which results (DV) are actually caused by manipulation of the IV.
(Whether there is cause and effect relationship)
What is external validity?
Extent to which results can be generalised to real life
- Ecological = apply to different settings
- Temporal = apply to different time periods
What is reliability?
Consistency of data and the way its gathered
