research methods overview Flashcards
define aim
- doesn’t make a prediction but instead it states what is it that we want to look at.
- it is a statement of what the researcher intends to find out in a research study
what is a directional hypothesis
- indicates the direction of the prediction
- e.g. ‘music will negatively effect recall’
what is a non-directional hypothesis
- states something is going to happen but not the direction of the prediction.
- e.g. ‘there will be a difference in recall between the music and no music condition’
what is a null hypothesis
-predicts that there will be no difference, only difference is just due to chance
independent variable
- the thing the researcher is able to manipulate between the different conditions
- the thing that is changed
dependent variable
-the thing that is measured
how do you operationalise hypotheses/IV’s/DV’s . How do you make it measurable ?
ask yourself can I count this easily? If the answer is no then it is not operationalised
situational variables
- things to do with the situation
- e.g. lighting, instructions, time of day.
- overcome by standardisation (making everything the same for all conditions)
participant variables
- things to do with the participants
- e.g. age, Intelligence, gender, personality
- overcome by random allocation or measured/matched participants
what are the two extraneous variables
situational variables
participant variables
confounding variable
a type of IV that varies systematically between conditions
investigator effects
-an experimenter may accidentally give cues to make partisans respond in a certain way
- can be over come by;
1. using standardised instructions to stop the experimenter leading the participant.
2. using a double blind technique where both the participants and the experimenter don’t know the aim of the experiment
independent measures
-group of participants, split them in half. Half of the participants do the first condition of the IV and the second half do the 2nd condition of the IV. Compare the performance of both groups.
evaluation of independent measures
advantage = you don’t get order effect as participants are only doing one condition of the IV so they don’t get use to what’s happening.
disadvantage =no control of participant variables and you need twice as many participants
overcoming these problems = random allocation of participants which theoretically distributes participant variables evenly.
repeated measures
-group of participants take part in all levels of the IV. Same participants in all conditions of the IV
evaluation of repeated measures
Advantage = fewer participants. No individual differences as participants are taking part in all conditions of the IV
Disadvantage = you might get an order effect. Participants may do better on 2nd test due to practice effect. May guess experiment purpose and change their behaviour.
overcoming these problems = use 2 different tests to reduce practice effect. Counterbalancing can be used to deal with order effect- cover story can be presented to the participants about the purpose of the test.
matched Paris design
- 2 groups of participants but match them on key characteristics believed to effect performance on the DV
- 1 member of pair is allocated to group a and the other group b. Procedure is then the same for independent groups.
evaluation of matched pairs design
advantages = controls some participant variables, participants won’t guess the studies aim. As a result of having different participants for each condition there is no order effect.
disadvantages = achieving matched pairs is difficult and time consuming. May not control all participant variables
overcoming these problems = restrict the no. of variables to the matched one. A pilot study to show key variables that need to be matched
random sampling
- everyone in the target population has an equal chance of being selected.
- can be done through generating random numbers of simply picking names out of a hat.
opportunity sample
-people who are available at the time the study is carried out. e.g. people in the common room.
volunteer sample
-participants are recruited for through an advert, newspaper, Internet etc
systematic sample
- a system is used to select participants e.g. every 4th person to leave the canteen. The numerical interval is applied consistently.
stratified sampling
- subgroups within the population are identified e.g. gender.
- participants are obtained from each of the subgroups in proportion to their occurrence in the population
- selection from the strata is done using a random technique
1 strength and 1 weakness of random sampling
strength = least biased weakness = difficult to achieve in practice as target population could be huge so time consuming
1 strength and 1 weakness of volunteer sampling
strength = gives access to a variety of participants weakness = tends to be a certain type of person that volunteers. e.g. highly motivated, so could be biased
1 strength and 1 weakness of opportunity sampling
strength = easy and less time consuming to allocate sample
weakness = biased as sample is drawn from a small part of the population
1 strength and 1 weakness of stratified sampling
strength = less biased as proportional and randomly selected representation of subgroups weakness = time consuming to identify subgroups and then randomly select participants
1 advantage and 1 disadvantage of systemic sampling
advantage = unbiased as participants are selected using an objective system weakness = not truly unbiased unless you select a number using a random method and start with this person and then selected every nth person.
lab experiment
- involves manipulation of IV whilst trying to keep all other variables content.
- participants are aware they are taking part in an experiment but may be unsure of the true aims of the study
field experiment
- the IV is manipulated in a natural setting e.g on a train
- participants are often unaware that they are taking part in the experiment
natural experiment
- study in which a naturally occurring IV is investigated
- the IV is not deliberately manipulated by the researcher
- generally used when it’s not possible/practical ethically to manipulate the IV
Quasi experiment
- IV is naturally occurring
- DV can be measured in a lab
- key feature is that the IV isn’t actually ‘manipulated’ or made to vary by anyone-it is simply a difference that exists.
- e.g, gender as the IV
naturalistic observation
- carried out in everyday setting
- investigator doesn’t interfere in any way but just observes the behaviours
controlled observation
-behaviour is observed but under conditions where certain variables have been organised by the researcher
overt observation
participants are aware that their behaviour is being studied