Psychology: The Experimental Methods Flashcards
What is the difference between an aim and a hypothesis?
The aim ISA general statement that describes the purpose of a study e.g. to see if time of day effects student performance.
This doesn’t predict the outcome of the research, the hypotheses does state this.
What is a non directional Hypothesis?
Non directional hypotheses state that an effect will occur also known as two-tailed hypotheses
What is a directional Hypothesis?
Directional hypotheses predict the direction of the effect also known as one-tailed hypotheses
How to write a Directional Hypothesis?
- There will be a difference between…..with more/less…in the….
- People who….will do better/worse than…. *
How to write a Non-Directional Hypothesis?
- There will be a difference between…..
When do you write a non-directional hypothesis and when a directional and when the dependent variable?
- Most hypotheses are directional (one-tailed) because there is evidence (usually past research) to suggest that it is likely.
- Non-directional hypotheses are used when there is contradictory evidence and it is difficult to predict which direction of the results.
What is an independent variable?
A factor which is usually manipulated by the researcher
What is an dependent variable?
The factor you measure in the experiment and is affected by the independent variable
What is Operationalisation?
Clearly defining variables in terms of how they can be measured - to make it measurable
There is a difference in children’s reading ability depending on whether they have blue or brown eyes - Directional or Non-Directional
Non-Directional
Dogs that are rewarded with treats sit when told to do so more often that dogs that are not rewarded with treats - Directional or Non-directional
Directional
What is an Independent groups/measures?
Different participants are used for the 2 conditions of the IV
Problem: participant variable groups
What is a Repeated Measure?
The same participants are used for both conditions of the IV
What is a Matched Pair?
Different participants are for the 2 conditions, but each group is matched on characteristics relevent to the study.
Why is random allocation used?
To prevent biase from the researcher
Why does task difficulty need to be controlled in a repeated measure design?
So that the test is as balanced and accurate as possible
What are the strengths and limitations of Repeated Measures?
- No participants variables
Limintations: - Order effects are a problem
- Demand Charcterists more likely
What are the strengths and limitations of Independent groups?
Limitations:
- Participant variables - these may affect the DV instead of change in IV
- More participants needed
What are the strengths and limitations of Matched Pairs Design?
Strengths:
- Less partcipants needed
- No participant variables
Limitations:
- Need information to match participants on
- Pre-test might be needed (expensive and time consuming)
What is a demand charcteristic?
- Sometimes demand characteristics make participant’s behave in the way they think the experimenter wants them to.
- Other times it makes participant’s behave in manner opposite to what they think expectations are.
In which experimental design are demand characteristics Moore likely to be problem?
Repeated measures
What is researcher bias/investigator effects?
- Loose procedures: not treating all participants in the same way.
- Subtle cues: (body language ect) that lead participants to behave in certain ways.
- Fudging results: e.g. missing out results that don’t ‘fit in’.
What is a Lab experiment?
Take place in a controlled environment
What is a Lab experiment strength?
- High Control Over Extraneous Variables
- High Internal Validity
- Repicatable
What is a Lab experiment limitation?
- Lack of generalisability
- High demand characteristics
- Low mundane realism
What is a field experiment?
The IV is manipulation in a more natural everyday setting. Participants are usually unaware they are in a study.
What is a field experiment strength?
- High external validity
What is a field experiment limitation?
- Lack of control over extraneous variables
- Hard to replicate
- Ethical Issues
What is a natural experiment?
Similar to a field experiment but the experimenter cannot control the independent variables - for either practical or ethical reasons.
The experiment occurs naturally. The experimenter just notices that conditions are like an experiment and records the findings.
What is a natural experiment strength?
- Provides opportunities for research where the experimenter isn’t able to manipulate the IV
- High External validity
What are natural experiment limitations?
- Difficult to replicate
- Participants are not randomly assigned to experimental conditions so hard to see if IV has caused the effect on the DV
What are Quasi experiment?
Have an IV based on an existing difference between people e.g. gender, age
What are Quasi experiment strengths?
Often carries out in controlled conditions so shares the same strengths as lab experiments.
What are Quasi experiment limitations?
Quasi experiments cannot randomly allocate people to experimental conditions therefore extraneous variables may affect outcome.
