Scientific processes (Research Methods) Flashcards
An ‘aim’ in research is…
A general statement of what the researcher wants to investigate
A hypothesis is
A clear testable statement that states a relationship or effect between variables
A one tailed hypothesis is
Directional - it predicts the direction of the outcome (e.g. which group will perform better)
A two tailed hypothsis is
Non directional - it predicts there will be a difference/relationship but not in which direction
When do researchers tend to use a directional hypothesis?
When there is previous research on the topic
When do researchers tend to use a non-directional hypothesis?
When there is no previous research or it is contradictory
Independent variable
the variable that the researcher MANIPULATES or that changes naturally (the cause)
Dependent variable
the variable the researcher MEASURES (the effect)
What is meant by ‘levels of the IV’
The experimental conditions participants are in e.g. if the IV is Amount of Caffeine the levels may be ‘Caffeine’ and ‘No Caffeine’
What is the term for clearly defining your variables in terms of how they can be measured?
Operationalisation
What is the ‘baseline’ condition called in an experiment?
Control group
An extraneous variable is
A variable outside of the IV which has the capability to affect the DV if not controlled
How is an extraneous variable different to a confounding variable?
EVs dont systematically vary with the DV so have the capability to affect the DV is not controlled. CVs do vary with the IV so it’s impossible to tell if this has affected the DV or not! It has confounded our results!
Participants react to cues from the researcher/environment and this is known as
Participant reactivity
These are cues from the research regarding the AIM which lead to the potential of participants changing their behaviour.
Demand characteristics
What are the behavioural consequences of demand characteristics?
The please-U effect (over-perform to please the researcher) or the screw-U effect (underperform to sabotage the research).
The investigator may (consciously or unconsciously) affect the participant’s behaviour, this is known as…
Investigator effects
A method to control the effects of bias when designing materials and deciding the order of experimental conditions
Randomisation
A method of controlling for investigator effects by keeping all procedures the same for each participant
Standardisation
A control method where the participant is not aware of the research aims to prevent demand characteristics
Single blind procedure
A control method where the participant is not aware of the research aims to prevent demand characteristics and the researcher is not aware of the aims to prevent researcher bias
Double Blind Procedure
What is meant by experimental designs?
The different ways in which participants are organised in relation to the experimental conditions
Name the experimental design: different participants complete different levels of the IV and the two separate groups are compared.
Independent measures design
Name the experimental design: Pairs of participants are matched on a variable relevant to the DV with one being assigned to condition A and the other to B. The two separate groups are then compared.
Matched pairs design
Name the experimental design: all participants take part in all conditions of the experiment and the two groups are them compared.
Repeated measures design
1 strength and 1 weakness of an independent measures deign
+ no order effects, less chance of demand characteristics
- more participant variables, more time consuming and costly
1 strength and 1 weakness of repeated measures design
+ controls for participant variables, more economical
- more chance of order effects, more chance of demand characteristics
1 strength and 1 weakness of a matched pairs design
+ controls for participant variables, reduces order effects and demand characteristics
- can never match participants exactly, time consuming/costly
What is meant by order effects?
Performance in a second set of conditions is improved (practice effect) or worsened (fatigue/boredom effect) compared to the first
How might you control for order effects?
Counterbalancing or use an independent measures design
What is counterbalancing?
the ABBA technique - participants complete the conditions in different order to spread out order effects.
How can you control participant variables?
Repeated measures design, matched pairs design, random allocation to conditions
What is meant by the ‘population’
A group of people who are the focus of the research from which the sample are drawn
The group of people who take part in the research and are presumed to represent a larger target population are called…
Sample
The methods used to collect your sample are collectively known as
Sampling techniques
What is meant by a random sample?
All members of the target population have an equal chance of being selected for the sample
How is a random sample collected?
- Get a complete list of all names of people in the target population
- assign each name a number
- use a lottery method to select X amount (picking from a hat, computer method)
1 Strength and 1 weakness of random sampling
+ potentially unbiases due to the laws of chance = increase internal validity
- time consuming and could still be unrepresentative particularly is some refuse to take part (then its more like a volunteer sample)
What is systematic sampling?
Selecting every nth person in a population
How is a systematic sample collected?
- Create a sampling frame (organised list of everyone in the population e.g. alphabetical)
- Choose a sampling system (every 3rd or 5th for example)
- start your sampling from a random point
1 Strength and 1 weakness of systematic sampling
+ Objective as the researcher has no influence over participant selection
- time consuming and if participants refuse it becomes biased like a volunteer sample
What is stratified sampling?
Where the composition of a sample matches the composition of a population based on its subgroups (or strata)
How is a stratified sample collected?
- Identify the strata (or sub groups)
- Work out the representative proportions of each strata for the sample
- Use random sampling to select the number needed in each strata
1 Strength and 1 weakness of Stratified Sampling
+ representative as it reflects the proportions of the population
- cannot represent all differences so can’t get a completely accurate representation of the population
What is opportunity sampling?
The sample is made up of anyone is is willing and available at the time of the research