psyc311 – development psychology ch 01 research methods

Psyc311 – Development Psychology

Ch 01Research Methods

Developmental Periods

• Prenatal (conception to birth)• Infancy (birth to 18-24 mos)• Early Childhood (2-5 years)• Middle Childhood (6-11 years)• Adolescence (10-12 to 18-21 years)• Early Adulthood (20s to 30s)• Middle Adulthood (40s to 50s)• Late Adulthood (60-70s to death)

Developmental Periods

• Prenatal (conception to birth)• Infancy (birth to 18-24 mos)• Early Childhood (2-5 years)• Middle Childhood (6-11 years)• Adolescence (10-12 to 18-21 yrs)• Early Adulthood (20s to 30s)• Middle Adulthood (40s to 50s)• Late Adulthood (60-70s to death)

Age Group 1

Age Group 2

Age Group 3

Week Tues Thurs Topic/Reading

1/11Intro to Devel; Syllabus

Ch 1. Research Methodology Section 1: Introduction

1/18Grp Research Proposal Q/

Psyc Info: Look up articles Ch 4-6 Section 3: Infancy

1/25Grp Article Summary -- Intro;

Methods Section Ch 4-6 Section 3: Infancy

2/1Ch 4-6; Grp Proposal

Discussion Ch 4-6; Taking Sides Section 3: Infancy

2/8 Ch 7-8 Ch 7-8; Grp Prop 1st Draft Section 4: Early Childhood

2/15 Ch 7-8 Ch 7-8; Taking Sides Section 4: Early Childhood

2/22 Exam 1 Ch 11-12; Obs Journal 1 Section 6: Adolescence

3/1 Ch 11-12 Ch 11-12 Section 6: Adolescence

3/8 No Class: Spring Brk No Class: Spring Brk  

3/15 Ch 11-12; Grp Prop 2nd Draft Ch 11-12; Taking Sides Section 6: Adolescence

3/22Grp Prop Peer Review; Obs

Journal 2 Grp Prop Peer Review; Ch 13-14 Section 8: Early Adulthood

3/29 Ch 13-14 Ch 13-14 Section 8: Early Adulthood

4/5 Exam 2 Ch 17-19 Section 9: Late Adulthood

4/12 Ch 17-19 Ch 17-19; Grp Prop Final Draft Section 9: Late Adulthood

4/19 Grp Presentations Grp Presentations  

4/26READING DAY;

Volunteer Project Due

Obs Journal 3 or Exam 3 and Final exam:

10:50 class - 5/1, 8-11am 1:40 class - 5/4, 12-3pm  

top choices for topicssocial/moral development

self/personality/identity development

developmental disorders (e.g., ADHD, autism)

romantic relationships (dating, marriage)

emotional development

health issues/problems

parenting/family relationships

friends/peer relationships

puberty/sexual development

death/dying

pretend play/imagination

gender development

effects of aging -- physical, cognitive, social

Characteristics of Development• Lifelong• Multidimensional

– Biological, cognitive, socio-emotional• Multidirectional

– Expansion/contraction• Plastic

– Gene/environment interaction• Multidisciplinary• Contextual

– Age-graded influence– History-graded influence– Non-normative (individual)

Developmental Science

Five steps1. Ask a (developmental) research

question.

Developmental Science

Five steps1. Ask a (developmental) research

question.2. Develop a hypothesis.

Developmental Science

Five steps1. Ask a (developmental) research

question.2. Develop a hypothesis.3. Construct a methodology to test

your hypothesis.

Developmental Science

Five steps1. Ask a (developmental) research

question.2. Develop a hypothesis.3. Construct a methodology to test

your hypothesis.4. Draw a conclusion.

Developmental Science

Five steps1. Ask a (developmental) research

question.2. Develop a hypothesis.3. Construct a methodology to test

your hypothesis.4. Draw a conclusion.5. Share your findings.

Research questions

Does god exist?• Is this a good research question?

•NO!!

Research questions

Good research questions must involve something that can be empirically defined and measured.

• Operational definition– the description of the variable of interest in

measurable terms.

• So, how might we operationally define:– Aggression– Happiness

• Measurement– Device used to detect the events/phenomena

to which the operational definition refers.With this in mind, let’s generate some

research questions of our own.

• Which is the best research q?– A) Alcoholic parents tend to neglect their

children more than non-alcoholic parents.– B) What factors influence high school

dating?– C) Does the frequency and graphic quality

of violence in video games influence levels of anti-social thinking in adolescent males?

– D) How much longer until class is over?– E) None of these are good.

Developing hypotheses

• Developing a hypothesis: – What do you think you’ll find?

• Why?– That is, what is your

(theoretical/conceptual/empirical) justification for you hypothesis?

Testing hypotheses• How are you going to test your

hypothesis?

• Non-experimental Design– Observation of variables of interest

• Experimental Design– Manipulation of variables of interest

Testing hypotheses

Types of measurement• Subjective measures

– Introspective reports– Survey/Questionnaire

• Objective measures– Standardized testing– Naturalistic observation

• Physiological Measurements– fMRI, galvanic skin response– Levels of hormones, neurotransmitters

Research designs• Case study• Target age group• Developmental – several age groups

• Cross sectional• Benefits – cheap way to capture change over time• Problems – cohort effect and other group differences• Longitudinal• Benefits – confidence that change being captured is

genuine change• Problems – reduction of sample size and learning

effect• Cross-sequential

Time 1 Time 2

2nd

4th

6th

4th

6th

8th

Time 1 Time 2

2nd

4th

6th

4th

6th

8th

Design considerations• Validity• Being able to draw accurate inferences

(conclusions) about what you are studying from your measurements

• Invalid in definition– Examples?

• Invalid in detection (measurement)– Examples?

• Reliability• The tendency for measurement to produce the same

results when used in the same way (or under the same conditions).– Type 1 error (false positive)– You want a measurement that is stable enough that it won’t

detect changes in your variable when changes haven’t actually occurred.

• Power• The tendency for measurement to produce different

results when used in different ways (or under different conditions). – Type 2 error (false negative)– You want a measurement that is sensitive enough to detect

changes in your variable when changes actually occur…

population and sample

• You are asking a question about behavior in a given population– It is difficult (if not

impossible) to ever study an entire population – so what do we study instead?

teenagers

population and sample

• You are asking a question about behavior in a given population– It is difficult (if

not impossible) to ever study an entire population – so what do we study instead?

• a sample.

teenagers

• How do we make sure that we can accurately generalize from a sample to a population?

• We choose a representative sample.– controlled or random

sampling

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describing data

•Central tendency

•mode—most frequent

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describing data

•Central tendency

•mode—most frequent

•mean—average

Μ = 3.27

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describing data

•Central tendency

•mode—most frequent

•mean—average•median—

middle

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describing data

•Central tendency•mode—most

frequent•mean—average•median—middle•Each of these

tells us something different about our data.

normal distribution• Many things tend to

be normally distributed in a given population.

• So, we should expect most people to fall somewhere close to the middle, with the extreme cases being less frequent.

IQ is normally distributed.

mean

33

describing data

•Variability– range

7 – 1 = 6

relationships between variables

• What is a correlation?• Relationship between two variables

– A is related to B– Positive relationship: A+/B+, A-/B-– Negative relationship: A+/B-, A-/B+

what kind of correlation?• As a person gets angrier, they also get

more violent.– A) Positive correlation– B) Negative correlation

• Positive. As anger increases, violence increases.

• As a person gets older, they start to remember fewer vocabulary words.– A) Positive correlation– B) Negative correlation

• Negative. As age increases, vocabulary memory decreases.

• As calorie consumption drops, people have less energy.– A) Positive correlation.– B) Negative correlation.

• Positive. As calorie consumption decreases, energy levels decrease (so variable movement is happening in the same direction).

relations between variables: causation

Ultimately, we are typically interested in whether or not one variable causes another.

T/F: All variables that are causally related are correlated.

T/F: All variables that are correlated are causally related.

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•Two variables are correlated– X Y

•three possible relationships

X causes Y

Y causes X

Z causes both X and Y

– with correlation, we cannot know which it is.

third variable problem: Classic example

+

+

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experimentation

•To establish causation, we must conduct an experiment.

•Experimentation requires manipulation

•A B

•A is the independent variable -- manipulated• e.g., amount of television violence watched

•B is the dependent variable -- measured• e.g., amount of aggressive behavior exhibited

Violent TV

Non-violent TV

experimentation

• In the case of a 3rd variable, you have two choices:

• Manipulate and measure x & y, while controlling for z.

or• Manipulate and

measure x, y, & z.

randomization (controls for 3rd variable)

• used when z is not important for the study

selected groups (measures influence of 3rd variable)

• Used when z is important for the study Adult supervision No adult supervision

other considerations: drawing conclusions

• Internal validity– Study is designed so that you are able to draw

accurate inferences about causal relation between independent and dependent variables.

• External validity– Study designed so that your independent and

dependent variables are defined in natural/realistic way.

• You can have internal validity but not have external validity – why?

other considerations: biases

• Biases in observation– Participant biases

• Demand characteristics

– Observer biases• Confirmation bias

Double-blind experiments

other considerations: ethics

• Ethical practices– Informed consent– Debriefing– Special considerations for children

• Are there things we shouldn’t study?

Final steps

• Drawing conclusions– What kinds of conclusions can you

draw?– Can you generalize to a population?

• How broad of a population?

– Limitations

• Sharing your findings– Conference presentations– Publications