L2 - Variables, types of data and validity Flashcards
What is an independent variable?
The variable we manipulate.
What is the dependent variable?
The variable that DEPENDS on the manipulation of the IV.
What do “levels” mean in regards to measuring your IV?
How many conditions (levels) of the IV there are. e.g. when measuring emotion you could also subsequently be measuring memory.
What is a between-subjects design?
Split groups; Different participants do different tests.
What is a within-subjects desing?
Every participant does the same test.
What are one-tailed and two-tailed hypotheses?
one-tailed = directional prediction (e.g. People who drank coffee will be quicker at the test than those who drank water)
two-tailed = non-directional prediction (e.g. There will be a difference in speed of the test taken between the coffee and water drinker groups).
What is an experimental hypotheses?
AKA: Research hypotheses OR alternative hypotheses (Ha).
This is a claim that the independent variable will have an effect on the dependent variable.
What is a null hypotheses?
(Ho) This is supported when there is a less than significant effect reported of the experimental hypotheses (e.g. the IV had no effect on the DV as originally predicted).
What is discrete data?
Data that can only be reported in whole numbers/integers e.g. amount of people, number of cars parked, amount of trees in the park.
What is continuous data?
Data that can assume any value within a specified range that usually changes over time e.g. Temperature, speed, weight, time taken to do a task.
What is nominal data?
Categorical data that cannot be ranked or measured in a specific order e.g. eye colour, dog breed, marital status, names of countries.
What is ordinal data?
Categorical data that can be ranked based on it’s relative value however the distances between the categories cannot be equally defined e.g. Letter grades (A, B, C), movie ratings, economic class, opinions (agree, neutral, disagree).
what is interval data?
Measured, ordered numerical data that has equal distance between each data point but no meaningful zero and it cannot be multiplied/divided but can be a negative e.g. dates, time on clock (1pm, 6pm), ph level, IQ. (you cannot say 6pm is twice as big as 3pm OR you cannot say someone with an IQ of 150 is 3 times as smart as someone with an IQ of 50).
What is ratio data?
Measured, ordered numerical data that has equal distance between each data point AND a meaningful zero but cannot be a negative number e.g. age, time intervals (1.5 seconds, 8 seconds), weight, height.
What is the difference between experimental and quasi-experimental designs?
Experimental (AKA True experimental) seeks to establish a cause and effect relationship between the IV and the DV and randomises it’s participants, quasi-experimental seeks to establish the same but participants are assigned to specific groups based on non-random criteria.
