chapter 1 Main Idea notes Flashcards
what is a construct
A construct is a topic that you are actually studying—this is often a variable that cannot be directly observed.
ex: intelligence
what is an operational definition?
An operational definition the behaviors that are representative of the construct. Something that displays the construct
ex: if the construct is intelligence it would be IQ
population
The entire set of individuals that you purport to study.
sample
The relatively small subset of scores or individuals that you have available to observe
what is a characteristic that describes a sample
statistic
what is a characteristic that describes a population?
parameter
sampling error
The discrepancy, or amount of difference, that exists between the results from your sample and what the results would be had you tested the entire population.
is a sample ever identical to the population?
no
what makes a sample “good”
- randomly selected from the population of interest.
- representative of the population: Characteristics of sample reflect those of the population of interest.
what sample size is better small or large
large
descriptive statistics
Organizing & summarizing the data (“number crunching”).
ex: # of covid cases, Average G.P.A. in this class, Most typical college major in class, Average height etc
inferential statistics
techniques, based on probability, that allow us to generalize beyond our sample to the population. Based on probability. ex: Average g.p.a at BU (inferred from this class)
Predictions about elections (b/c they are inferred from a small sample)The effectiveness of a covid vaccine within a population.
do most scientific articles include descriptive or inferential statistics?
both
does correlation mean causation
NO
correlational study
Measure two things and determine whether there is a relationship between them; nothing is manipulated by the researcher
third variable problem
A correlation between X and Y may be caused by some other variable (Z) that is not measured.
ex: Ice cream sales and shark attacks are related.
directionality problem
Even if two variables are causally linked, you can’t tell which is the cause and which is the effect.
Ex: relationship between violent video games and aggression or between social media use and depression. What is the cause and what is the effect
experimental study
- A researcher manipulates a variable and measures the effect on another variable while holding everything else constant.
- Control everything else that may impact the variable of interest
dependent variable
The behavior that is measured by the experimenter.
Exam score
Reaction Time
Level of Depression
# of covid infections
independent variable
The variable that is manipulated by the experimenter to see if it affects the behavior of interest.
ex: hours of sleep
alcohol consumption
do correlational studies have independent variables?
no they have 2 dependent
whats another word for independent variables
factors
conditions
The specific amounts of the IV used in the experiment. sometimes called levels of the IV
ex: for hours of sleep the conditions would be 4hrs, 6hrs. 8hs
quasi independent variables
Groups of people that can be compared, but cannot ever be true IVs, because you cannot randomly assign to groups. Need to interpret cautiously (as you would a correlational study)
examples of quasi-independent variables
sex, gender identity, age, race, ethnicity, college major, religion
quantitive vs qualitative
quantitative is amount, qualitative is a category
ratio scale
quantitative there is a 0 point included
interval scale
quantitative, ordered categories of the same size, ranking something on a scale from 1 to 10
ordinal data
order and ranking, quantitative. distances dont need to be uniform, ex: olympic medals, ice cream, movies
what are likert scales
strongly agree, agree, neutral, disagree, strongly disagree theyre considered interval
nominal data
name qualitative doesnt differ in amount only different categories ex: major, race, religion