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
Participant reactivity
when the responses and/or behaviours of study participants are affected by their awareness that they are part of a study
can lead to :
- demand characteristics
-investigator effects
Randomisation
used in the presentation of trials in an experiment to avoid any systematic errors that might occurs as a result of the order in which the trials take place.
Standardisation
using the exact same formalised procedures and instructions for every single participant involved in the research process
-eliminates non standardised instructions as being possible extraneous variables
Laboratory experiment
Conducted in a highly controlled environment, where the researcher manipulates the IV and records the effect on the DV.
- Strict control is maintained over extraneous variables
Strength of Laboratory experiment
- High internal validity due to control over extraneous variables = Researcher can ensure any effect on the DV is due to their manipulation of the IV + proves cause and effect. ( high degree of control )
- Results are more replicable = Results are valid and generalisable :
Limitations of Laboratory experiments
- Lacks ecological validity = Not true to real world so can’t be generalised
- Hawthorne effect = behaviour is altered due to awareness of the study.
- Demand characteristics = participants are aware of study due to lab conditions so behaviour is unnatural.
Field experiment
Conducted in a natural environment where the researcher manipulates the IV and records the effect on the DV.
e.g Hoflings hospital study on obedience
Strength of field experiments
- High mundane realism = Environment is more natural, so behaviour is more valid + authentic.
- High external validity = Participants are unaware of study.
Limitations of field experiments
- Lack of informed consent = ethical issues, invasion of privacy.
- Increased realism also increases extraneous variables = Cause and effect of IV + DV is harder to establish and precise replication won’t be possible.
Definition of Natural experiment
Researcher takes advantage of a pre-existing IV.
- Natural as the variable would’ve changed regardless of the researchers interest in it.
e.g : biological explanations of bullying
Strengths of natural experiment
- Provide research opportunities for studies that can’t be conducted due to ethical/practical reasons.
- High external validity = involves study of real situations
Limitation of natural experiment
- Naturally occurring event is rare = limits scope for generalising results to other similar situations.
- Participants may not be allocated randomly to experimental conditions = less clarity that the effect on DV is due to the IV.
Quasi experiment
IV isn’t determined by anyone, but is not manipulated and an existing difference between people. (age , gender, phobias)
e.g A memory task with a group of clinically depressed participants compared to a control group of non-depressed participants
Strength of Quasi experiments
- High internal validity due to control over extraneous variables = Researcher can ensure any effect on the DV is due to their manipulation of the IV + proves cause and effect.
- Conducted under highly controlled conditions = replicable, reliable, generalisable results.
Limitation of quasi experiments
- Can’t randomly allocate participants to conditions = possibility of confounding variables
Population
A group of people from whom samples are drawn
Generalisation
The extent to which research results can be applied to the population.
Sample
A group of people who take part in a research investigation, chosen from a population.
Bias
When certain groups may be over or under-represented within the selected sample
= limits extent of generalisation.
Random sampling
- Obtain a list of the population and assign numbers
- Randomly choose sample via lottery method (random number generator or names in a hat)
Strengths of random sampling
- No researcher bias = unable to choose samples to support their hypothesis.
- Everyone has an equal chance of being chosen
- Laws of probability = likely to be representative
Limitation of random sampling
- Difficult and time consuming to obtain a list of the population.
- Possibility of unrepresentative sample = doesn’t reflect the distribution of characteristics in the population.
- Participants may refuse to participate = becomes a volunteer sample.
Systematic sampling
- Sampling frame is produced = list of population in alphabetical number.
- Sampling system is made = every nth member of the population is chosen.
Strength of systematic sampling
No researcher bias = researcher has no influence over chosen people after the sampling system is chosen.
- Fairly representative
Limitation of systematic sampling
- Complete representation isn’t possible = doesn’t reflect all differences in people.
Stratified sampling
- Identify the different strata within the population + work out the proportion needed from each strata to be representative.
- Use random sampling to choose people from each strata.
Strength of stratified sampling
- No researcher bias = sample from strata is random and uninfluenced by the researcher.
- Representative = designed to accurately reflect composition of the population, so generalisation is possible.
Limitation of stratified sampling
- Complete representation isn’t possible = can’t reflect all the ways people are different.
Opportunity sampling
- Select anyone willing + available by asking anyone around at the time of their study. (e.g the streets)
- participants available at the time of study
Strength of opportunity sampling
- Convenient : easy method of recruitment
- Saves time and effort
- Less costly
Limitation of opportunity sampling
- 2 forms of Bias:
= Researcher bias as they have complete control over the selection.
= Unrepresentative as chosen from a specific area so can’t be generalised.
Volunteer sampling
- Participants select themselves to be apart of the sample (e.g raising hands/advert)
strength of volunteer sampling
- Requires minimal researcher input : willing participants , more likely to co-operate
- Less time-consuming
Limitation of volunteer sampling
Volunteer bias = attracts helpful, curious people so generalisation may be difficult.
- motivation like money could be driving participants so participants may not take study as seriously
independant group design
Two separate groups experience two different conditions of the experiment.
- One group takes part in condition A and the other group takes part in condition B.
- Performances of the groups are compared
Limitation and resolution of independant group design
- Researcher can’t control participant variables = different abilities of participants
Randomly allocate participants to conditions so the participant variables are distributed evenly.
- Needs more participants
Strengths of independent group design
no order effects : e.g practise effect or boredom effec
- Can use the same test for both groups = faster
- Participants are less likely to guess aim
Repeated measures design
Only one group of participants and they take part in both conditions
Limitation and resolutions of repeated measures design
- Order effect may affect performance (participants may perform better/worse in the second condition due to practice/boredom)
= Use 2 different tests to reduce practice effect, so the order effect is dealt with via counterbalancing.
- During the second test, participants may guess the aim of the experiment which affects their behaviour
= Use deception and lie about the aim + use distractor questions
Strength of repeated measures design
- Limits the variability between participants
- Fewer participants needed
Matched pairs design
Two separate groups, but they’re matched into pairs for certain qualities before splitting (age,gender,intelligence).
each person from a pair goes into a different experimental condition
Limitations and resolution of matched pair design
- Very time consuming + difficult to match participants based on key variables = Restrict number of variables to match
- Not possible to control all participant variables = Conduct a pilot study to consider key variables that may be important when matching.
Strengths of matched pair design
- Reduces participant variables as researcher has paired the participants, so each condition has people with similar abilities + characteristics.
- Avoids order effects, so no counterbalancing is needed.
demand characteristics less of a problem
hawthorne effect
When an individual modifies an aspect of their behaviour, due to their awareness of being observed.
Mudane realism
The extent to which the materials + procedures involved in a study are similar to events that occur in the real world.
External validity
Extent of results being applicable to other experiments, settings, people, and times.
Naturalistic observation
Watching and recording behaviour in a setting where it would normally occur.
Strength of naturalistic observation
- High ecological validity = results can be generalised to everyday life as behaviour is observed in a natural env
- No researcher influence
- People are less likely to alter their behaviour as they’re unaware of the observation + it’s not controlled
Limitation of naturalistic obervation
- Low internal validity = no control over extraneous variables, so it confounds + difficult to judge behaviour patterns.
- Hard to replicate = due to no control and extraneous variables.
Controlled obervation
Watching and recording behaviour within a structured environment, where variables are controlled
Strengths of controlled observation
- Replicable = easy to show reliability + generalisable after repeating.
- No confounding variables due to control
Limitation of controlled observation
- Reducing naturalness of environment + behaviour = due to regulating variables.
- Demand characteristics + low ecological validity = Participants know they’re being studied
Covert observation
Participants behaviour is watched and recorded WITHOUT their knowledge/consent.
Strengths of covert observation
- High ecological validity
- Removes participant reactivity = behaviour is natural as they’re unaware of the observation.
- Authentic
limitation of covert observation
- Unethical = lack of informed consent + deception
- Intrusive = lack of privacy
- No control over variables
Overt obervation
Participants behaviour is watched and recorded WITH their knowledge/consent.
Strength of overt observation
- Ethically acceptable = informed consent + the right to withdraw is given.
limitation of overt observation
- Hawthorne effect = altered behaviour due to awareness of observation.
- Demand characteristics affect data
Participant observation
Researcher becomes a member of the group being watched and recorded.
Limitation of participant observation
- Subjective and biased = observation made by someone that actively participated in the activity being observed.
- Researcher ‘goes native’= line between researcher and participant is blurred
Non-participant observation
Researcher doesn’t become involved with the group being watched and recorded.
eval of Non-participant observation
- Lack of direct involvement = objective and less likely to ‘go native’
- Easier to observe and record data.
limitation of non participant observation
Loss of valuable insight = may miss some things
Self reporting techniques
A method where a person is asked to state their own feelings, opinions and experiences related to a topic:
Example: questionnaires, interviews
Questionaires
A set of pre-written questions used to collect data by assessing a person’s thought or experiences.
- May be used to assess the DV
- Always structured
Advantages of questionnaires
Directly observing intentions/feelings = Reduces assumption.
- Can be distributed to a large sample = good for generalisation.
- May be more willing to share personal information.
Disadvantages of questionnaires
- People may be untruthful = due to social desirability bias.
- Completed by people that can read/write = limits sample.
- ‘Eager sample’ = filled by people who have time/want to fill them so the sample is biased.
- Acquiscence bias = tendency to agree to content without reading q’s properly.