research methods y1&2 Flashcards
what is an experimental method?
- manipulation of IV
- so that the IV can have an effect on the DV
- which is measured and stated in results
what are the 4 types of experimental methods?
- quasi
-laboratory
-field
-natural
what is an independent variable
the variable that the experimenter changes / manipulates
- e.g : temperature of the room ( experimenter changes this , to see the change in maths scores )
what is a dependant variable
- variable being tested and measured in an experiment
- it is “dependant” on the independent variable
e.g : measuring the maths scores of participants in different temp conditions
Aim
general statement that the researcher intends to investigate
Hypothesis
A detailed statement which is clear, precise and testable that states the relationship between variables being tested.
Directional hypothesis
The researcher makes it clear what difference is anticipated between the 2 conditions or groups.
Clear effect of iv on dv
(One tailed).
e.g “ “The more sleep a participant has the better their memory performance.”
Non-directional hypothesis
Simply states that there is a difference but not what the difference will be.
e.g : “The difference in the amount of hours of sleep a participant has will have an effect on their memory performance, which will be shown by the difference in the memory test scores of the participants.”
Why must factors that effect the DV be controlled?
- extraneous variables
- confounding variables
- to make sure that the effect on the DV is purely due to the independant variable
How would you test the effect of an IV
Compare the different experimental conditions:
- Control condition (e.g no energy drink/water) = used to determine whether the IV affected the DV.
- Experimental condition (e.g energy drink)
Operationalisation
Clearly defining variables on terms of how they can be measured = makes the hypothesis clear + testable.
Example: After drinking 500ml of energy drink, participants speak more words in the next 5 minutes than participants who drink 500ml of water.
(even more operationalised : number of words said)
Extraneous variables
Any unwanted variables outside of the IV that will impact the DV.
- Researcher should minimise the influence (control) or remove these variables.
e.g : lighting of lab or age of participants
Confounding variable
An uncontrolled extraneous variable that change systematically with the IV and affect the DV, so results won’t show the effect of the intended IV.
e.g : time of day
to control : all participants take test same time of day
state 3 types of extraneous variables
- Participant variables
- Situational variables
- Investigator effects
Outline examples of participant variables
- Personality
- Age
- Intelligence
- Gender
- Participant reactivity
Explain how to control Participant variables
-Sample: Use random sampling to gain a representative sample from the population.
-Design: Use repeated measures or matched pairs
Allocation: Randomly allocate them to conditions
Outline examples of situational variables
- Time of day
- Heat
- Demand characteristics
Explain how to control Situational variables
- Standardise: Keep everything the same for each participant (procedures and instruction)
- Counterbalance: Reduces effect of situational variables
Definition and examples of investigator effects
Subtle cues from a researcher that may affect the performance of participants in studies:
- Body language
- Tone/voice
- Bias
Explain how to control Investigator effects
- Double blind: Neither researcher nor participants knows which condition they’re in.
- Inter-rater: Independent raters rate the same behaviour as the researchers and check for agreements.
Outline the definition of counterbalancing
- participant sample is divided into a half
- one half completing the two conditions in one order
- the other half completing the conditions in the opposite order
- used to deal with order effects e.g when using a repeated measures design
Demand characteristics
A cue that makes participants unconsciously aware of the aims of a study and helps them work out what the researcher expects them to find.
- May behave in an unnatural way and over/under-perform to please the researcher = affects results/DV
How to control demand characteristics
- Deception: Use distractor questions and lie about the aim.
- Single blind: Participant is unaware of which condition they’re in.
What can demand characteristics cause?
Please-U effect : may act in a way they think the researcher wants them
Screw-U effect : intentionally underperform to sabotage the study’s results