Research Methods:Research Methods:

In Child PsychologyIn Child Psychology

Research plan:Research plan:

1.1. Theory Theory

2. 2. HypothesisHypothesis

3. 3. MethodMethod –to test hypothesis. –to test hypothesis.

4. 4. Conduct studyConduct study (gather data) (gather data)

5. 5. ConclusionsConclusions -- does data support our -- does data support our theory or not?theory or not?

Say we wanted to study all 5 yr-olds Say we wanted to study all 5 yr-olds

social behavior in the US?social behavior in the US?

Could we do this????Could we do this????

No!!! It would be too exhaustiveNo!!! It would be too exhaustive

Instead get a Instead get a representative samplerepresentative sample of 5-yr-olds of 5-yr-olds

That reflects entire population of 5 yr-olds in the US.That reflects entire population of 5 yr-olds in the US.

Poor Sample #1 Poor Sample #1

A researcher wants to study the way children’s A researcher wants to study the way children’s vocabularies change over time. Living near a private vocabularies change over time. Living near a private nursery school in a rather affluent suburban community, nursery school in a rather affluent suburban community, she selects thirty 3-year olds and thirty 5-year olds from she selects thirty 3-year olds and thirty 5-year olds from the school population and carefully tests their the school population and carefully tests their vocabulary levels. Based on the performance of these vocabulary levels. Based on the performance of these children of professional parents the investigator reports children of professional parents the investigator reports that she now has a set of norms or guidelines for what that she now has a set of norms or guidelines for what may be expected of preschooler’s vocabulary may be expected of preschooler’s vocabulary knowledge.knowledge.

What’s wrong with this sampleWhat’s wrong with this sample??????????

Problems with Sample #1Problems with Sample #1

1. Kids of professionals—tend to have larger vocabularies 1. Kids of professionals—tend to have larger vocabularies than kids of less educated folks. than kids of less educated folks.

2. Kids in this sample—not representative of kids across 2. Kids in this sample—not representative of kids across US. US.

3. This nursery school is likely to be superior in quality to a 3. This nursery school is likely to be superior in quality to a school in the ghetto. school in the ghetto.

Poor Sample #2Poor Sample #2 You are interested in the development of aggressive You are interested in the development of aggressive

behavior in children. You select a sample of children behavior in children. You select a sample of children who have been brought to a psychological clinic who have been brought to a psychological clinic because of family problems. There are 30 boys and 5 because of family problems. There are 30 boys and 5 girls in the sample, and all come from a poor part of a girls in the sample, and all come from a poor part of a large urban area. You evaluate various aspects of the large urban area. You evaluate various aspects of the children’s behavior by watching them play with other children’s behavior by watching them play with other children and by asking them how they would resolve a children and by asking them how they would resolve a dispute with a peer. You assess how well each child’s dispute with a peer. You assess how well each child’s parents get along and how much TV the children watch. parents get along and how much TV the children watch. Ultimately, you conclude that boys are more aggressive Ultimately, you conclude that boys are more aggressive than girls, and that aggression in children is related both than girls, and that aggression in children is related both to watching a lot of TV viewing and to parental fighting.to watching a lot of TV viewing and to parental fighting.

What’s wrong with this sampleWhat’s wrong with this sample???? ????

Problems: Sample 2Problems: Sample 2 1. Families who bring their kids to clinics—1. Families who bring their kids to clinics—

may be different than families who don’t.may be different than families who don’t.

2. Conclusions regarding gender cannot be 2. Conclusions regarding gender cannot be validly drawn from this sample.validly drawn from this sample.

3. Sample focuses on poor kids, not 3. Sample focuses on poor kids, not representative of kids in pop. representative of kids in pop.

National SurveyNational Survey

Is a nationally representative group of Is a nationally representative group of people. people.

E.g., National Longitudinal Survey of Youth E.g., National Longitudinal Survey of Youth (NLSY) started in 1979. (NLSY) started in 1979.

Survey participants—drawn from 235 areas, Survey participants—drawn from 235 areas, including 485 countries and cities across including 485 countries and cities across US.US.

Data CollectionData Collection

A. Self-Reports:A. Self-Reports:

1. Children’s Self-Reports1. Children’s Self-Reports

Problem’s with these???Problem’s with these???

On self reports, children may be:On self reports, children may be:

less attentiveless attentive slower to respondslower to respond Unable to understand questions.Unable to understand questions.

Kids should only be interviewed Kids should only be interviewed alonealone!!!!

Although usually truthful, kids will tend to be Although usually truthful, kids will tend to be less truthful less truthful if a parent is present during if a parent is present during questioningquestioning..

2. Self-reports: Family members:2. Self-reports: Family members:

1. Based on multiple observations over time in a 1. Based on multiple observations over time in a variety of situations. variety of situations.

2. The parent’s perceptions of the child can be 2. The parent’s perceptions of the child can be obtained. obtained.

3. What’s the family structure? 3. What’s the family structure?

Problems:Problems:

1. Parents--less likely to report problems with 1. Parents--less likely to report problems with their child’s development. their child’s development.

2. Parents may provide inaccurate reports of 2. Parents may provide inaccurate reports of their childcare practices. their childcare practices.

Why?????Why?????

Methods to improve family reports:Methods to improve family reports: 1.  Ask about recent events. 1.  Ask about recent events.    2.  Phone parents nightly & ask about 2.  Phone parents nightly & ask about

specific behaviors (hitting, etc.) specific behaviors (hitting, etc.)    3. Have parents keep behavior diary. 3. Have parents keep behavior diary.

4. Have parents carry (cell phone) to be 4. Have parents carry (cell phone) to be called at random times, to assess behavior. called at random times, to assess behavior.

3. Teachers and Peers may give reports:3. Teachers and Peers may give reports:

1. Ask child’s peers to “rate” how well liked 1. Ask child’s peers to “rate” how well liked he/she is (“I like playing with Jane alot.”)he/she is (“I like playing with Jane alot.”)

Tells you-- child’s social status!!Tells you-- child’s social status!!

2. Teachers--rate child’s performance in class 2. Teachers--rate child’s performance in class on several dimensions. on several dimensions.

B. Direct ObservationB. Direct Observation Allows us to see child in action.Allows us to see child in action.

Problems:Problems: 1. Children often act differently at home 1. Children often act differently at home

than at school. than at school.

2. People respond different when being 2. People respond different when being observed. observed.

Methods of observation:Methods of observation:

Specimen recordSpecimen record (records everything a child (records everything a child does for a fixed period of time). Gets broad range does for a fixed period of time). Gets broad range of behaviors.of behaviors.

Event samplingEvent sampling (only records instances when (only records instances when particular behavior occurs.)particular behavior occurs.)

Time samplingTime sampling (researcher checks off any of the (researcher checks off any of the behaviors listed on a sheet that occur during a behaviors listed on a sheet that occur during a predetermined time period). predetermined time period).

Correlation studiesCorrelation studies

Yields a measure of the strength and direction of Yields a measure of the strength and direction of the relationship between two or more factors. the relationship between two or more factors.

Correlation coefficient (–1.00 to +1.00)Correlation coefficient (–1.00 to +1.00)

SignSign (+ or -) of correlation indicates direction of (+ or -) of correlation indicates direction of relationship.relationship.

Number-indicates magnitude of relationship.Number-indicates magnitude of relationship.

Weight & Huston (1995) study:Weight & Huston (1995) study:

Studied TV viewing of preschool kids in low-Studied TV viewing of preschool kids in low-income areas.income areas.

Kids were 2 or 4 at start of study, 5 or 7 at end.Kids were 2 or 4 at start of study, 5 or 7 at end.

Parents recorded kids behavior (including TV Parents recorded kids behavior (including TV viewing). viewing).

Every year, kids took a variety of cognitive Every year, kids took a variety of cognitive achievement tests.achievement tests.

Findings:Findings:

Kids who watched educational TV (Sesame Kids who watched educational TV (Sesame Street) tended to have higher cognitive Street) tended to have higher cognitive achievement scores (r=.25, p<.05).achievement scores (r=.25, p<.05).

Regular TV was negatively correlated with Regular TV was negatively correlated with cognitive achievement.cognitive achievement.

Did watching Sesame Street cause the kids Did watching Sesame Street cause the kids higher test scores?higher test scores?

No causal inferences can be drawn here!No causal inferences can be drawn here!

1. Bright kids may be drawn to educational 1. Bright kids may be drawn to educational programs.programs.

2. Kids watching educational TV- may 2. Kids watching educational TV- may have parents who spend time educating have parents who spend time educating them. them.

Experiments: Does X cause Y?Experiments: Does X cause Y?

Two basic designs:Two basic designs:

1. Between-Subjects Design:1. Between-Subjects Design:

2. Within-subjects Design:2. Within-subjects Design:

Variables (factors)Variables (factors)

What is an independent variable (IV) ???What is an independent variable (IV) ???

What is dependent variable (DV) ??What is dependent variable (DV) ??

The IV is expected to influence the DV.The IV is expected to influence the DV.

Field Experiment- Friedrich & Stein (1973)Field Experiment- Friedrich & Stein (1973)Kids in nursery school --examined for 3 wks to get baseline Kids in nursery school --examined for 3 wks to get baseline

level of aggressive behavior. level of aggressive behavior.

Then over 4 wk period, kids watched 30 min. of TV a Then over 4 wk period, kids watched 30 min. of TV a day. Kids randomly assigned to 1 of 3 groups.day. Kids randomly assigned to 1 of 3 groups.

Group 1: aggressive (Batman cartoons)Group 1: aggressive (Batman cartoons) Group 2: gentle (Mr. Rogers)Group 2: gentle (Mr. Rogers) Group 3: neutral (circus shows).Group 3: neutral (circus shows). Recorded kids aggressive behavior following TV Recorded kids aggressive behavior following TV

exposure.exposure.

Results:Results:

Kids (high in baseline aggression) acted Kids (high in baseline aggression) acted more aggressively after watching the more aggressively after watching the Batman cartoons, than the other types of Batman cartoons, than the other types of shows. shows.

Kids low in aggression showed no change Kids low in aggression showed no change after watching Batman.after watching Batman.

Case Study:Case Study:

Study one child for an extensive period of Study one child for an extensive period of time.time.

Allows for an in-depth look at a particular Allows for an in-depth look at a particular phenomenon. phenomenon.

Studying Change over timeStudying Change over time

The Cross-Sectional methodThe Cross-Sectional method – study – study several age groups simultaneously.several age groups simultaneously.

The Longitudinal Method – The Longitudinal Method – study same study same individuals for extended period of time. individuals for extended period of time.

Sequential MethodSequential Method