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Designing Designs for Research
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Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

Dec 21, 2015

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Page 1: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

Designing Designs for Research

Page 2: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

Designing Designs

How do you establish causecause? How do you minimize threats minimize threats to

validity? How do you construct construct a design? What is a goodgood design?

Page 3: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Establish Cause?

Temporal PrecedenceTemporal Precedence

Page 4: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Establish Cause?

Temporal precedenceTemporal precedence

CauseCause EffectEffectthenthen

Time

Page 5: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Establish Cause?

Temporal precedenceTemporal precedence

CauseCause EffectEffectthenthen

Time

Why is this important?Why is this important?

Page 6: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Establish Cause?

Temporal precedenceTemporal precedence

CauseCause EffectEffectthenthen

Time

Why is this important?Why is this important?

Cyclical functionsCyclical functions

Inflation

Unemployment

Page 7: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Establish Cause?

Temporal PrecedenceTemporal Precedence

Covariation of Cause and EffectCovariation of Cause and Effect

CauseCause EffectEffectthenthen

TimeTime

Page 8: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Establish Cause?

Temporal precedenceTemporal precedence

Covariation of cause and effectCovariation of cause and effect

CauseCause EffectEffectthenthen

timetime

If X, then Y.If X, then Y.If If notnot X, then X, then notnot Y. Y.

Page 9: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Establish Cause?

Temporal precedenceTemporal precedence

Covariation of cause and effectCovariation of cause and effect

CauseCause EffectEffectthenthen

timetime

If X, then Y.If X, then Y.If If notnot X, then X, then notnot Y. Y.

If program given, then outcome observed.If program not given, then outcome not observed.

Page 10: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Establish Cause?

Temporal precedenceTemporal precedence

Covariation of cause and effectCovariation of cause and effect

CauseCause EffectEffectthenthen

timetime

If X, then Y.If X, then Y.If If notnot X, then X, then notnot Y. Y.

If program given, then outcome observed.If program not given, then outcome not observed.

If more of program, then more of outcome observed.If less of program given, then less of outcome observed.

Page 11: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Establish Cause?

Temporal precedenceTemporal precedence

Covariation of cause and effectCovariation of cause and effect

No alternative explanationsNo alternative explanations

CauseCause EffectEffectthenthen

timetime

If X, then Y.If X, then Y.If If notnot X, then X, then notnot Y. Y.

Page 12: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Establish Cause?

Temporal precedenceTemporal precedence

Covariation of cause and effectCovariation of cause and effect

No alternative explanationsNo alternative explanations

CauseCause EffectEffectthenthen

timetime

If X, then Y.If X, then Y.If If notnot X, then X, then notnot Y. Y.

ProgramProgram OutcomeOutcomecauses?

Page 13: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Establish Cause?

Temporal precedenceTemporal precedence

Covariation of cause and effectCovariation of cause and effect

No alternative explanationsNo alternative explanations

CauseCause EffectEffectthenthen

timetime

If X, then Y.If X, then Y.If If notnot X, then X, then notnot Y. Y.

ProgramProgram OutcomeOutcomeCauses?

Alternativecause

Alternativecause

Alternativecause

Alternativecause

Page 14: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

In Typical Outcome Evaluation

Is taken care of because you intervene before you measure outcome

Is taken care of because you control the intervention

Is the central issue of internal validity -- usually taken care of through your design

Temporal Precedence

Covariation of Cause and Effect

No Alternative Explanations

Page 15: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Minimize Threats to Validity?

By argument By measurement or observation By design By analysis By preventive action

Page 16: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Minimize Threats to Validity?

By argumentBy argument

Page 17: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Minimize Threats to Validity?

By argumentBy argument

Simply say the threat isn’t reasonable.

Page 18: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Minimize Threats to Validity?

By measurementBy measurement

Page 19: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Minimize Threats to Validity?

By measurementBy measurement

Measure that the threat didn’t happen.

Page 20: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Minimize Threats to Validity?

By designBy design

R O X OR O X O

MaturationMaturationthreat?threat?

Page 21: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Minimize Threats to Validity?

By designBy design

Add a group to control for the threat.

R O X OR O OR O X OR O O

To address aTo address amaturationmaturation

threatthreat

Page 22: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Minimize Threats to Validity?

By analysisBy analysis

Mortality threat : Are your dropoutsMortality threat : Are your dropoutsdifferent from those retained indifferent from those retained in

your study?your study?

Page 23: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Minimize Threats to Validity?

By analysisBy analysis

Show through analysis that the threat isn’t plausible.

Retained Drop-Out05

1015202530

Retained Drop-Out

PretestPretestPretestmeansmeans

Page 24: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Minimize Threats to Validity?

By preventive actionBy preventive action

Rivalry?

Page 25: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Minimize Threats to Validity?

By preventive actionBy preventive action

Don’t allow the threat to happen in the first place.

Rivalry

Get programGet programnext semesternext semester

Page 26: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Across time Across programs Across observations Across groups

Expand...

Page 27: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Start with the simplest design.

Page 28: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

X OX O

Start with the simplest design.

Page 29: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Expand across timetime..

Page 30: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Expand across timetime..

O O X OO O X O

O X O O OO X O O O

Page 31: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Expand across programsprograms..

Page 32: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Expand across programsprograms..

O X1 OO X2 OO X3 O

O X1 OO X2 OO X3 O

ProgramProgramvariationsvariations

Page 33: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Expand across observationsobservations..

Page 34: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Expand across observationsobservations..

O1 X O1,2,3

O1 O1,2,3

O1 X O1,2,3

O1 O1,2,3

MeasurementMeasurementvariationsvariations

Page 35: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Expand across groupsgroups..

R O X OR O OR O X OR O O

Page 36: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Expand across groupsgroups..

R O X OR O OR O X OR O O

R O X OR O OR O X OR O OAdd aAdd a

replicate.replicate.

Page 37: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Expand across groups and timegroups and time..

R O X OR O O

N O

R O X OR O O

N O

Page 38: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Expand across groups and timegroups and time..

R O X OR O O

N O

R O X OR O O

N O

Page 39: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

Expand across groups and timegroups and time..

R O X OR O O

N O

R O X OR O O

N O

TimeTime

GroupsGroups

Page 40: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

X OStart

Page 41: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

X OStart

Expand

R O X O O

R O O X O

N O X O

N O O

Page 42: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

How Do You Construct a Design?

X OStart

Expand

R O X O O

R O O X O

N O X O

N O O

R O X O

R O O

N O OContract

Page 43: Designing Designs for Research. Designing Designs cause u How do you establish cause? minimize threats u How do you minimize threats to validity? construct.

What Is a Good Design?

Theory-grounded Situational (adapted) Feasible Redundant Efficient