Paper 2 Flashcards
What is an experiment?
An experiment is an investigation looking for a casual relationship where the IV is manupilated and expected to be responsible for the changes in the DV
What is an experimantal condition and a control condition?
Experimental - One of more of the situation in an experiment which represents different levels of the IV and are compared
Control - A level of the IV in an experiment from which the IV is absent. It is compared to one or more experimental conditions
What is an experimental design and what are the type?
An experimental design is the way that participants are used in different levels of the IV
1) Independent measures design
2) Repeated measures design
3) Matched pairs design
Describe the 3 experimental designs
1) Independent measures design - A different group of participants are used for each level of the IV.
2) Repeated measures design - Each participant performs in every level of the IV
3) Matched pairs design - Particiapnts are arranged into pair and a member of each performs a different level of the IV. Each pair is similiar in ways that are important to the study.
What are demand characteristics?
Features of the experimental situation which gives away the aims.
Can cause the participants to change their behavior and so reduces validity
What is random allocation and participant variables?
Random allocation - a way to reducedthe effect of confounding variables such as individual differences. participants will have equal chance of being in any condition
Participant variables are the individual differences.
What are order effects?
They can cause changes in performance between the conditions that are not due to the IV and so can obscure the effect on the DV
What are the 2 types of order effects. Describe them.
1) Practise effect - Participants performance improve due to familiarity or have learned the task
2) Fatigue effect - Participants performance has declined due to boredem or tiredness
What is counter balancing?
Counterbalancing is used to overcome order effects in a repeated measures design. Each possible order of levels of the IV is performed by a different sub group of participants
Strengths of independent measures design
- No order effects
- No demand characteristics
- Random allocations helps reduce effects of individual differences
Weaknesses of Independent measures design
- Participants can disort the results if there are important individual differences between them in different levels of the IV
- More participants are needed than repeated measures design. less ethical if harmed and less effective is sample small
Strengths in repeated mesures design
- Participant variables are unlikely to disort results as they go through all levels of the IV
- Counterblalcnign done to reduce order effects
- Less participants used
Weaknesses in repeated measures design
- Order effects
- Demand characteristics
Evaluate matched participants design
Strengths
* No demand characterisitics
* No effect for participant variables
* No order effects
Weaknesses
* Similiarity in pairs is limited by the matching process so the right criteris must be chosen before for this to be effective
* Sample size could be small as availability of matching pairs may be limited
What is standardisation?
The process of keeping the procedure exactly the same for all participants
What is reliability?
The extent to which a procedure is consistent and produces consistent results
What is validity?
The extent in which the researcher is testing what they claim to be testing
What is a laboratory experiment?
A research method with strict controls conducted in an artificial setting
What is meant by generalise?
Apply the findings of the study more widely
What is ecological validity?
The extent to which the findings of research in one situation would generalise to other situations. Influenced by whether it represents the real world well and if it is relavent to real life.(Mundane realism)
What is a field experiment?
An experiment conducted in a natural environment
What is a natural experiment?
This is not a true experiment as the IV cannot be manupilated by the experimenter. Instead they study the effcet of the exsisting difference.
Evaluate laboratory experiments
Strengths
* Good control of extraneous variab;es
* Casual relationship determined so high validity
* Standardised procedure so high reliability
Weaknesses
* Demand characteristics
* Low ecological validity
Evaluate Field experiments
Strengths
* No demand characteristics
* High ecological validity
Weaknesses
* Ethics
* Less control so low reliability
* Low validity
What are the strengths of natural experiments
- No demand characteristics
- High ecological validity
- Allows researchers to investigate variables that are not practical or ethical to manupilate
- Allows to study real world problems
What are the weaknesses of natural experiments?
- Only possible when the differences occur
- less control
- low validity as we dont know if there is a direct link between IV and DV
- Hard to replicate
What is a quasi experiment?
The researcher have lots of control over the procedure but not over the allocation of participants
What are questionnairs?
Research mtheod using written answers
What are the types of questions in a questionnaire?
- Close ended
- Open ended
Describe the two types of questions in a quetionnaire.
- Close ended- has a fixed set of answers to chose from
- Open ended - asks for descriptive answers from the taker’s own words
Evaluate close ended quetsions
Quantitative data
* Easier to analyze as it is not affected by researcher bias.
* simple to summarize
* Responses are limited
Evaluate Open ended questions
Qualitative data
* Produces detailed indepth reponses
* Research bias
* difficult to quantify
Evaluate questionnairs in general
- Lacks inter rater reliability when 2 researchers interpret the results
- Easy for participants to ignore questions
- Social desirability bias