Class 3 Notes - Variables + Constants

Question 1

Variables have at least

Answer 1

two levels.

• Can take on more
• Do you like ice cream? Yes or no? - 2 variables
• Do you like ice cream? Yes, no, or a little bit? - 3 variables

Question 2

Constants have

Answer 2

only one level.

How many people have COVID-19?
• Examining a constant

What percentage of people have COVID-19?
• Dealing with a variable
• Either you do, or you don’t have COVID-19

Question 3

Variables are either

Answer 3

measured or manipulated

Question 4

• Measure:

Answer 4

whether ppl are in a happy or sad mood - asking with clipboard

Question 5

• Manipulate:

Answer 5

systematically changing people to be at one level or another - showing people a video that induces happiness or sadness/giving people writing prompts

Question 6

Variables are defined either

Answer 6

conceptually or operationally

• Concrete things, actually assessing/manipulating
• For any given concept, like happiness, thousand different ways to manipulate the concept

Question 7

Conceptual variable:

Answer 7

• Boredom, an emotional state
• It is not a thing, physical object
• Bc we cannot count up boredom, we have to operationally define boredom - put it into concrete terms
• Boredom is commonly seen as an affective state compose of lack of stimulation, low physiological arousal, and unpleasant feelings
• How to measure boredom? Surveys, physiological measures (brain activity pattern, skin conductance, pupil dilation), observer ratings
• (Conceptual or theoretical definition vs. Operational definition)

Question 8

Identify a variable. Identify a constant.

Answer 8

Identify an operational variable.
• 3 different time periods: Feb.-Apr., May-July, Aug-Election Day
• 2 different types of news: fake news, mainstream news - would need to come up with operational definitions for these variables

Identify a constant.
• Engagement: everything depicted in this figure is engagement

Identify an operational variable.
• Decisions about how many time period to use
• Important consequences is the interpretation of data
• Engagement that occur one day apart from each other, could be sorted in very separate bin of time - April 31st vs May 1st

Identify a conceptual variable
• Time itself
• Time is abstract
• Seconds/minutes/categorizations of time

Question 9

3 claims

Answer 9

frequency

association

cause-and-effect claims

Question 10

frequency

Answer 10

only assess one variable, one constant

o 1 in 25 teens attempts suicide

o 44% of Americans struggle to stay happy

o 58% of Boulder residents exercise frequently

Question 11

association claim

Answer 11

two measured variables

o Shy people are better at reading facial expressions

o People who multitask the most are the worst at it

o Screen time not linked to physical activity in kids

Question 12

causal claim

Answer 12

indicator words of causality enhance, give, curb more exciting, dramatic words

o Music lessons enhance IQ

o Whiff of rosemary give your brain a boost

o Family meals curb teen eating disorder

Question 13

association or causal?

Answer 13

next slides (A/C)

Question 14

(A/C)

• Boredom makes people more creative

Answer 14

o Causal; makes

Question 15

• Memories work better in colour

A/C

Answer 15

o Causal; work better

Question 16

• Millennials dedicate an hour a week to selfies
A/C

Answer 16

o Frequency claim; constant (millennials) and a variable (amount of time taking selfies)

Question 17

• Your IG filters could predict if you’ll suffer from depression
A/C

Answer 17

o Association; predict

o Can be reversed/flipped - true either way (cause and effect only work in one direction)

Question 18

A/C

• People who met their spouse online score slightly higher on marital satisfaction

Answer 18

o Association; slightly higher

Question 19

a/c

• Viewing cat videos boost energy and positive emotions

Answer 19

o Causal; boost

Question 20

• Kids who eat cereal and milk for breakfast have a healthier body weight than kids who skip breakfast
a/c

Answer 20

o Association; can be flipped; a prediction

Question 21

• Putting your kids to bed earlier might improve their mental health
a/c

Answer 21

o Causal statement; improve implies cause and effect

Question 22

4 validities

Answer 22

• construct
• external
• internal
• statistical

Question 23

construct validity

Answer 23

o The transition from conceptual variable to operational variable

o How well was variable defined/measured

Question 24

external validity

Answer 24

o Do the results, apply to difference people/situations/real world?

o Do they generalize over the course of time? 20 years from now?

o How far can we push the finding, still being accurate

Question 25

internal validity

Answer 25

o Our confidence in being able to identify the true cause of the result

o 3rd variables? Confounds?

Question 26

statistical validity

Answer 26

o Are the statistics appropriate for the research design?

o Do the statements correspond with the data?

Question 27

Relationship between variables

Answer 27

• Is age related to physical activity?
o Do younger or older people exercise more?
 Conceptual variables: age, physical activity
 Operational definition for physical activity: as the number of miles people run per week

• Is distraction while studying related to exam performance?
o Do people perform better when they are not distracted, than when distracted?

Question 28

simple relationship between quantitative variables

Answer 28

• Positive
• Negative
• No relationship
• Correlation coefficient - r
• Curvilinear

Question 29

scatterplot lines

Answer 29

• The steepness of the line
o The steeper the line: stronger relationship

• The degree to which each of those dots miss the line
o Farther from line: weaker relationship
o Closer to line: stronger relationship

Question 30

Two Ways of Studying Relationships

Answer 30

• Non-experimental method:
o do not manipulate
o only measure
o can not make inferences of causality

• Experimental method:
o manipulate variables
o allows us to make inferences of causality

Question 31

non-experimental advantages + disadvantages

Answer 31

•	Advantages
   o	Natural behaviour, no interference
        	Example, littering behaviour
   o	Some variables cannot be manipulated
        	Example, height/sex
   o	Great for prediction
        	Bc we can closely replicate real-world
   o	Can be efficient

• Disadvantages
o No experimental interference = no control
o No causal inference
o 3rd variable problem: wealth might cause both happiness and exercise, when we try to measure the relationship between H & E, we might be measuring an unknown 3rd variable (ex. wealth)

Question 32

Problems with non-experimental methods

Answer 32

• Unknown direction of cause and effect
o Does exercise cause happiness?
o Or does happiness cause exercise?

• Uncontrolled 3rd variables
o Perhaps wealth causes both happiness and exercise?
o If so, exercise and happiness will appear to be related, even when they are not causally related

Question 33

experimental method advantages + disadvantages

Answer 33

• Allows cause and effect inferences!
• Manipulate variable 1 and observe the effect on variable 2

• Control all other variables

• Advantages
o Causal inferences
o High researcher control
o Can observe small or transient effects
 The number of milliseconds to identify a word

• Disadvantages
o Unrealistic
o Crappy predictions
o Not always possible to manipulate variables (participant variables: age, height, sex, gender)

Question 34

effect of IV on the DV

Answer 34

• Does distraction cause poor academic performance on an exam?

• Independent variable: distraction - is the cause
o “cause”
o Aka, manipulated/situational variable or IV
o Variable that we manipulate, or change

• Dependent variable - academic performance
o “Effect”
o “Depends” on manipulated variable
o Aka, outcome/response/measured variable
o Variable that we measure

Question 35

participant variable

Answer 35

• Characteristics that participants bring to study
• Background learning/knowledge

• Biological characteristics
o Right/left handed
o Personality traits
o Sex

• Usually cannot (ethically) manipulate
o Quasi-experimental

Question 36

establishing causality

Answer 36

1) Covariation, or relationship, between IV and DV variables

2) Temporal precedence
o Causes must precede effects
o IV precedes DV

3) Eliminate alternative explanations, or third variables/confounds
o IV is the only variable impacting DV

Question 37

eliminating alternative

Answer 37

• Experimental Control
o Extraneous variables are held constant

• Randomization
o Random assignment of participants to conditions
o Run the conditions of the study in a random order

• Some other variable could not cause the relationship between X and Y

Question 38

confounds

Answer 38

• Confound is a variable that a researcher manipulates that is not directly related to the hypothesis
o Confounds must covary with IV
 When the IV is present, confound is present
 When the IV is absent, confound is absent
o Confounds must cause change in DV

Question 39

confound example

Answer 39

• hypothesis: listening to relaxing music improves test performance
• method: randomly assign participants to either wear headphones and play relaxing music or a control condition
• IV: listening to soft music vs control
• DV: test performance

Question 40

Example: Music and Exam-Anxiety

Answer 40

• Confounding variable: variable that researcher manipulates that is not directly related to the hypothesis
• Must vary with IV
• Must cause change in DV

Question 41

Internal Validity

Answer 41

 What does it mean for something to be valid? Is the phenomenon, the finding, real? (Or is is a fluke?)

 Internal validity = is the cause valid

 Why isn’t soft music a valid cause?
o Uncertainty about whether soft music is the cause - it could be the presence of headphones
o Special treatment could be a 3rd variable
o Internal validity is low

 Experimental control = best friend of internal validity
o Random assignment - control participant variables