Terms Flashcards
What is a condition
The ‘groups you are testing
What is an independent variable?
What the researcher manipulates to ensure that it’s present in one condition and not the other.
All conditions treated the same, apart from the one with the IV
What is a dependent variable?
A behaviour that is measured, observed or recorded from the introduction of the IV.
What is a control condition?
The condition where the IV is absent
What is an experimental condition?
The condition where the IV is present
What is an extraneous variable?
A variable, other than the IV, that is present in one condition and not the other. Needs to be controlled and made constant across the two conditions
It has the POTENTIAL to influence the DV in an experiment
What is a confounding variable?
A type of extraneous variable that is related to both variables we are interested in, and is often to do with the participants
For example, you may find that in your study, the people who you put in one condition or group may all be of a particular personality type, meaning that personality becomes a second, unintended independent variable. Therefore, personality is a confounding variable.
It DOES have an unwanted effect on the DV in the experiment. Results are bias because cannot be seen if result was due to influence of IV or confounding variable.
What is a variable?
Something whose value changes over time (noun)
What is a controlled experiment
Way of studying the effects of a change in one variable (IV) to the value of another (DV) whilst attempting to control all extraneous variables
What is an independent measures design?
Participants only appear in one condition of the experiment. Conditions A and B have different personnel.
What are the advantages and disadvantages of an independent measures design?
A: Participants less likely to display demand characteristics
A: No order effects
D: Participant variables across two conditions
D: Need to recruit more participants to cover both conditions
What is a repeated measures design?
Participants appear in both conditioins of the experiment. Conditions A and B have the same participants.
What are the advantages and disadvantages of a repeated measures design?
A: Need to recruit fewer participants as everyone does both conditions
A: No participant variables across the two conditions
D: Order effects - fatigue and practice effects
D: Demand characteristics could be present as they have worked out the test
What is a matched pairs design?
Experimenter pre-tests participants in relation to the extraneous variables she is trying to control.
Participants then assigned to separate groups
What are the advantages and disadvantages to a matched pairs design?
A: No order effects as participants only doing one condition
A: reduced effect of participant variables
D: Time consuming
D: Need more participants
D: Still have participant variables as not everyone the same
What is counter balancing?
A way of dealing with the order effects (fatigue and practice) in experiments that have a repeated measures design.
Order is an extraneous variable that needs addressing, by making constant across the two conditions. So conditions presented in all possible orders to participants.
What is experimenter bias?
Happens when the researcher knows the experiments aims and may influence the outcome to conform to these expectations
What is ecological validity?
The degree to which the behaviours / results from a study reflect the behaviours that occur in natural settings
What is a field experiment?
Controlled experiment done in a NATURAL SETTING
Study the effect of a change in one variable (IV) on the value of another (DV) whilst attempting to control all EV
What is a laboratory experiment?
A controlled experiment done in a laboratory
Study the effect of a change in one variable (IV) on the value of another (DV) whilst attempting to control all EV
What is a quasi experiment?
These studies have an independent variable which is based on an existing difference between people, for example age or gender. The independent variable is not manipulated by anyone, it just simply exists.
What is a longitudinal study?
Researcher assessess the responses of the same individual/s on two or more occasions in their life
What is a cross-sectional study?
Researcher collects data from different aged people at the same time.
The data is collected from people who are similar in other characteristics but different in a key factor of interest, such as age, income level or location
What is a sequential study?
Study several age groups over a long period of time.
Recruiting participants
What is random sampling?
Everyone in sampling population has an equal chance of being selected as a participant
probability based
Recruiting participants
What is stratified sampling?
Randomly recruit participants but to sub-categories relevent to your study
e.g. separate sampling population into males and females, then randomly choose 25 of each so you have an even number of m and f participants
probability based
Systemic sampling, what is it?
Nominate a system in which every 5th / 10th/ Xth person is selected
probability based
What is quota sampling?
Particiant who meets specific criteria for my study
non-probablity based
What is Snowball sampling?
Word of mouth sampling, usually used for illegal activity research
non-probability based sampling
What is convenience / opportunity sampling?
Accidental, participants selected based on naturally occuring groups
e.g. want to research primary school kids, go to a school and use a class
non-probability based sampling
What are correlating variables
Values of variables alter at same time
What is positive correlation?
When an increase (or decrease) in value of one variable is accompanied by an increase (or decrease) in value of another
What is a negative correlation?
When an increase (or decrease) in value of one variable is accompanied by a decrease (or increase) in value of another
What is the correlation co-efficient?
A number between -1 and +1 measuring the degree to which pairs of variables are correlated
What does a correlation coefficient of -1 mean?
Perfect negative correlation: 2 values of variables move in opposite directions
e.g. the hotter it gets, the less jumpers i need
What does a correlation coefficient of +1 mean?
Perfect positive correlation: 2 values of variables increase or decrease together
e.g. the more I eat, the fatter i get
What is descriptive statistics?
Made raw scores from data easier to digest. Used to encapsulate the most important findings from a study
What is a null hypothesis?
When you predict there will be no difference between the two samples of scores on a particular variable.
If a difference is shown, we ‘reject the null hypothesis’
What is an experimental hypothesis?
When you predict there will be a difference between the two samples of scores on a particular variable.
What are levels of measurement?
A way of quantifying behaviour an presenting data
What does NOIR stand for
Nominal
Ordinal
Interval
Ratio
What does Nominal mean?
data is presented in separate discrete groups or categories.
Participant scores are put in one group or another.
What does Ordinal mean?
data scores are presented in rank order.
Shows position relative to other participants in the group.
What does Interval level of measurement mean?
Data is presented as scores on a scale with equal units.
You find out HOW much better participants did between one another
What is ratio levels of measurement?
Data is scaled but you have an absolute zero
What are discrete variables?
Nominal and ordinal
Measurements that are unable to be divided or separated, they reflect the categories. E.G Vote labour or conservative or green etc
What are continuous variables?
Interval and Ratio
- Divisble units of measurements.
- Can be divided continuouslly into smaller levels of units. E.G Km > m > cm > mm > nm…
- Gives a precise answer
What makes a good experiment? What are the three things it needs to demonstrate?
Cause and effect. This needs to demonstrate 3 things
- Is there an association?
- Time order of events
- Non-spuriousness (falseness)
