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-
44
Survey Review
• Share out some of your survey questions
• What controls must be in place for a survey to be valid?
6
Experimentation
Like other sciences, experimentation is the backbone of psychology research.
Experiments isolate causes and their effects.
Exploring Cause and Effect
8
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
9
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
10
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
12
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
13
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