In your Interactive Notebook: Unit.Day 1.5

Experiment Design 101

• Today’s OBJECTIVE(S) -- WRITE THESE DOWN:– I can correctly distinguish between

dependent and independent variables

• DAILY COMMENTARY– Explain why it is

important to have controls on experiments, and name two.

• TURN IN:– Place DQ’s in can.– Big Shot/Career Posters– Surveys

ON YOUR DESK: 1) reading journal2) Daily commentary notebook3)

Unit 1 ESSENTIAL QUESTIONS: What is (and isn’t) Psychology?How do psychologists conduct reliable and ethical research?

Assignment Log

• Due/Past Due– Reading Journals 1.2,

1.4, & 1.5– Commentary on

Psychological perspectives (via edmodo)

– Big Shot/Career Posters– Survey Design– Friday Quiz #1

• Coming Up– Experiment Project– Reading Journals 1.6,

1.7, 1.8– First FRQ (Free Response

Question)– Friday Quiz #2– Unit 1 Exam– Daily Commentaries

Today’s Discussion Questions

• Make sure your name is on the questions you submit, and that your question is unique. – This will be factored into your grade.

DQ’S, Updates & Reminders

• BIG PICTURE– Friday Quizzes

• September 6

– Projects Due• Friday, September 5th

– Experiment Project

– Unit Exam: • Monday, September 9th

• Today:– Lecture & guided practice– Partner Work– Independent Practice

• Tonight’s Homework: – Vocab Cards: modify or

study all terms from Friday’s quiz, especially the ones you missed

– Experiment Project

– Get ahead if you want:• RJ 1.6

– Griggs 10-13 & 20-26– or Myers 30-35 & 39-

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Survey Review

• Share out some of your survey questions

• What controls must be in place for a survey to be valid?

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Experimentation

Like other sciences, experimentation is the backbone of psychology research.

Experiments isolate causes and their effects.

Exploring Cause and Effect

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ExperimentationA summary of steps during

experimentation.

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Many factors influence our behavior. Experiments (1) manipulate factors that interest us, while other factors are kept

under (2) control.

Effects generated by manipulated factors isolate cause and effect relationships.

Exploring Cause & Effect

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An Independent Variable is a factor manipulated by the experimenter. The effect of the independent variable is the

focus of the study. For example, when examining the effects of

breast feeding upon intelligence, breast feeding is the independent variable.

Independent Variable

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A Dependent Variable is a factor that may change in response to an independent variable. In psychology, it is usually a

behavior or a mental process.

For example, in our study on the effect of breast feeding upon intelligence,

intelligence is the dependent variable.

Dependent Variable

Independent Practice

• SpongeBob activity

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In evaluating drug therapies, patients and experimenter’s assistants should

remain unaware of which patients had the real treatment and which patients had the

placebo treatment.

Controls on Experiments

Double-blind Procedure

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Assigning participants to experimental (Breast-fed) and control (formula-fed)

conditions by random assignment minimizes pre-existing differences

between the two groups.

Controls on Experiments

Random Assignment

Controls on Expermients

• Operational Definitions– Required for replication• Involve numbers and must be quantifiable

– Weight– Dosage– Decibel – Etc.

Evaluating the Reliability of Experiments

• Confounding variables– Unpredictable (or unexpected) factors that may

skew the results• A heart rate study in which one subject was nearly hit by

a car on the way to the lab• Early “studies” of intelligence found correlations between

race and intelligence– Did not consider educational background, history of oppression,

etc.

• Replication – can someone else re-create the study and get similar results?

Evaluating the Reliability of Experiments

• Hawthorne Effect – people behave differently when they know that they are being studied

Experiment Analysis

• Read each experiment description– Identify the:• Hypothesis• Independent varaiable• Dependent variable• Control group• Experiment group• Design flaws in the experiment

Unit 1 Project

• Design your own experiment– Work in pairs (may have one group of 2)– Be creative (you are designing but not actually performing the

experiment)– BE SURE TO INCLUDE

• Hypothesis• Control group & experiment group• Dependent & independent variables• Discuss a potentially confounding variable• Be specific about 3 controls on the experiment• Explain how you would represent your results statistically

– Group with the most creative experiment gets 3 bonus points on our first exam

DQ’S, Updates & Reminders

• BIG PICTURE– Friday Quizzes

• September 6

– Projects Due• Friday, September 5th

– Experiment Project

– Unit Exam: • Monday, September 9th

• Today:– Lecture & guided practice– Partner Work– Independent Practice

• Tonight’s Homework: – Vocab Cards: modify or

study all terms from Friday’s quiz, especially the ones you missed

– Experiment Project

– Get ahead if you want:• RJ 1.6

– Griggs 10-13 & 20-26– or Myers 30-35 & 39-

44