L2

Question 1

5 methodological issues in experiments

Answer 1

reliability, file-drawer problem, validity, WEIRD subjects, experimenter bias

Question 2

Reliability

Answer 2

consistent results across multiple occasions, with different experimenters, across different labs/field sites

Question 3

Inter-rater reliability vs test-retest reliability

Answer 3

• different raters, same results
• same kid, different time, same results

Question 4

File-drawer problem

Answer 4

many studies don’t get published and sit in (virtual) file drawers as positive results are more likely to get published

Question 5

Validity

Answer 5

having a measure that accurately reflects the process or construct of interest

e.g. looking time and preference

Question 6

Internal validity

Answer 6

whether the observed effects can be attributed to what you’re measuring (dependent variable) and your manipulation (independent variable) without a confound

Question 7

External/ecological validity

Answer 7

whether or not the findings are generalizable to the general population (real world) or just the sample (lab)

Question 8

Potential solution to the WEIRD bias

Answer 8

ManyBabies projects where dozens or hundreds of labs around the world do the same study, estimate the size of the effect, and probe cross-cultural differences

Question 9

Attrition issues in infant studies

Answer 9

babies leaving the sample

Question 10

2 necessary conditions in conducting infancy research

Answer 10

measurement equivalence and control for everything to prevent confounds (e.g. parental influence)

measurement equivalence: the same construct is being measured across groups or across time

Question 11

Examples of recruitment methods in infancy research

Answer 11

birth records, hospital recruitment, buying mailing lists, facebook ads, posting flyers

Question 12

5 kinds of research designs

Answer 12

correlation, experiment, quasi-experiment, naturalistic observation, structured observation

Question 13

Correlation

Answer 13

values on 2 or more variables are observed and the relationship between them is assessed

Question 14

Benefits and limitations of correlational design

Answer 14

• can evaluate the direction and strength of the relationship between variables that may even be impossible or unethical to manipulate
• cannot draw causal conclusions (direction-of-causation problem) and third-variable problem

Question 15

Experiment

Answer 15

• participants are randomly assigned to conditions or groups
• experimenter manipulates the independent variable/s and measures the dependent variable/s

Question 16

Benefit vs limitation of experimental design

Answer 16

can make causal conclusions but some variables cannot be manipulated

Question 17

Between-subjects vs within-subjects experiments

Answer 17

• comparison between experimental group and control group
• each subject gets both experimental and control items

Question 18

Which kind of experimental design has more statistical power?

Answer 18

within-subjects

because individual differences are eliminated

Question 19

Quasi-experimental designs

Answer 19

natural variables (e.g. sex, age, SES) are treated as groups so members are not randomly assigned

Question 20

Limitations of quasi-experimental designs

Answer 20

• essentially correlational so difficult to conclude causality as third variables may be in play
• need to ensure groups match as closely as possible on other variables

Question 21

2 main designs for studying development (change over time)

Cross-sectional vs longitudinal design

Answer 21

• groups of different children of different ages are compared
• the same children are examined over time at different ages (collected at intervals of months or years)

Question 22

Benefits and limitations of cross-sectional design

Answer 22

• relatively fast and requires less commitment from families
• statistically less powerful due to potential individual differences and cohort differences

cohort differences: age differences are confounded with group differences

Question 23

Microgenetic design

Answer 23

type of longitudinal design wherein the same children are observed repeatedly after short intervals (e.g. daily, weekly) over a relatively short time period as they master a task (e.g. onset of crawling, first word learning)

Question 24

Benefits vs limitations of longitudinal design

Answer 24

• better information on developmental change and individual differences are not as influential
• expensive, time-consuming, cohort effects are masked, test-retest issues (e.g. practice effects)

Question 25

Cohort-sequential design

Answer 25

* combination of cross-sectional and longitudinal designs * different cohorts of children are tested over time with each starting the study at different ages

Question 26

Age-held constant design

Answer 26

all children studied are the same age but vary in some way that influences or contributes to development ## Footnote e.g. exposed to one language vs multiple languages

Question 27

Methods to measure infant preference

Answer 27

preferential looking, conditioned head-turn task, preferential reaching, high-amplitude sucking

Question 28

Habituation

Answer 28

inducing a negative preference (or boredom) for a stimulus through repeated exposure, resulting in dishabituation to a novel stimulus

Question 29

Comparator model ## Footnote explains habituation

Answer 29

we preferentially orient to stimuli that doesn't match our internal representations

Question 30

Violation of expectation

Answer 30

exposure to stimuli that is more/less interesting at baseline (without inducing a negative preference) will elicit a response from infants

Question 31

Imitation

Answer 31

a link between an infant's own actions and those of others (e.g. neonatal imitation)

Question 32

How can an infant's memory be tested?

Answer 32

deferred imitation paradigms

Question 33

Examples of physiological/neural measures

Answer 33

* autonomic nervous system activity (e.g. heart rate, blood pressure, stress hormones) * pupil dilation (measure of surprise/interest/concern) measured via eyetracker ## Footnote heart rate slows when interested and increases when afraid

Question 34

Pros vs cons of physiological/neural measures

Answer 34

* automatic and relatively objective * requires special equipment and training, has a debatable reason for response, and can be overhyped

Question 35

Hemodynamic response ## Footnote a neurological measure

Answer 35

* a measure of oxygenated blood flow that gives you a sense of which brain areas are active/passive with different stimuli/tasks * measured using MRI and fNIRS (functional near-infra-red spectroscopy) ## Footnote * Pros: non-invasive, good spatial resolution, can see big structural changes over time, and some functional activity (with fNIRS) * Cons: only a proxy for brain activity and has poor temporal resolution

Question 36

Hemodynamic response

Answer 36

a measure of oxygenated blood flow that gives you a sense of which brain areas are active or passive with different stimuli or tasks

Question 37

MRI vs fNIRS ## Footnote when used to measure hemodynamic response

Answer 37

* only performed when asleep, has a loud noise, and no movement allowed * sleeping not required, no loud noise, movement allowed

Question 38

EEG and Event-related potential (ERP)

Answer 38

a measure of electrical activity in the brain, at rest or following an event

Question 39

Pros vs cons of EEG and ERP

Answer 39

* good temporal resolution, non-invasive, and measures actual brain activity * poor spatial resolution