Basics Flashcards
What is a theory?
A theory is an explanation for an observation
What is a hypothesis?
A hypothesis is a prediction based on your theory, which you need data to then test.
What qualities should a good scientific theory have?
It should explain most (or all) of the data. It should allow one to make a general statement about that state of the world.
What is an independent variable?
A variable that we believe to be the cause of some effect. Its value does not depend on any other variables. Used in experimental research to denote a variable the experimenter has manipulated.
What is a dependent variable?
A variable thought to be affected by changes in an independent variable. It can be thought of as an outcome.
What is the ‘level of measurement’?
The relationship between what is being measured, and the numbers that represent what is being measured.
What levels of measurement do Categorical variables have?
Binary (only two categories), Nomimal (more than two categories), Ordinal (same as nominal but categories have a logical order).
What levels of measurement do Continuous variables have?
Interval (equal intervals represent equal differences on property being measured), Ratio (same as interval but ratios of scores on the scale must also make sense in reality).
What is a Construct?
A construct is a skill, attribute, or ability that is based on one or more established theories but is not directly observable (intelligence, anxiety, love). For example, the Beck Depression Inventory is able to measure depression, which is a construct.
What is the difference between validity and reliability?
Validity is whether an instrument actually measures what it sets out to measure (e.g. does the Beck Depression Inventory actually measure depression?). Reliability is whether an instrument can be interpreted consistently across different times and situations.
In what two ways can a distribution deviate from normal?
(1) lack of symmetry (called skew) and (2) pointyness (called kurtosis)
What do experimental methods strive to do?
To provide a comparison of situations (usually called treatments or conditions) in which the proposed cause (independent variable) is present or absent.
What is a between-subjects design?
Also called between-groups or independent design, it is a form of experiment whereby we manipulate the independent variable using different entities (groups). Different groups take part in each experimental condition.
What is a within-subject design?
Also called repeated-measures design, it is a type of experiment whereby the independent variable is manipulated using the same entities (groups). The whole group takes part in experimental conditions at different times.
What is the mode?
The score that occurs most frequently in the dataset.
