Day 6

January 29/30

Quiz #5

• 1. The ___________ variable is the factor that researchers manipulate so that they can determine its effect.
• 2. True or False: when an experiment uses control groups as well as experimental groups, it is called a controlled experiment.
• 3. What is a placebo?
• 4. What is the difference between a single-blind and a double-blind study?
• BONUS: A scientist studies the impact of room temperature on test scores. The independent variable is the __________. The dependent variable is the ____________.

independent

A substance or treatment that has no effect apart from a person’s belief in it.

In a double-blind study, both the experimenters and the participants do not know which group a participant is in.

temperature

test score

Hypothesis

• A hypothesis is an educated guess about how things work.
• Most of the time a hypothesis is written "If _____[I do this] _____, then _____[this]_____ will happen." (Fill in the blanks with the appropriate information from your own experiment.)
• Your hypothesis should be something that you can actually test- a testable hypothesis. In other words, you need to be able to measure both "what you do" and "what will happen."

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• If skin cancer is related to ultraviolet light , then people with a high exposure to UV light will have a higher frequency of skin cancer.
• If leaf color change is related to temperature , then exposing plants to low temperatures will result in changes in leaf color.

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• Not all if-then statements are hypotheses.
• "If I play the lottery, then I will get rich” is a prediction. In a testable hypothesis, a relationship is stated. For example, if the frequency of winning is related to frequency of buying lottery tickets, "Then" is followed by a prediction of what will happen if you increase or decrease the frequency of buying lottery tickets.
• If you always ask yourself if one thing is related to another, then you should be able to test it.

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Variables

• Independent- the one you control

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• Dependent- the one that you observe and/or measure the results.

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• Example: Room temperature and test scores

Operational Definitions

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• MUST be included in your hypothesis
• Necessary for replication of your study

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• Example: Older people are more intelligent.
• What is age? What is intelligence? How do you measure it?

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• Hypothesis: “If students are sleep deprived, then they will score significantly lower on a test.”
• What concepts do we need to define?

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First, what do we mean by students? In our example, let’s define students as participants enrolled in a introductory high school psychology course.

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Next, we need to operationally define the sleep deprivation variable. In our example, let’s say that sleep deprivation refers to those participants who have had less than five hours of sleep the night before the test.

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Finally, we need to create an operational definition for the test variable. For this example, the test variable will be defined as a student’s score on a chapter exam in the introductory psychology course.

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• Can your hypothesis be tested?
• Does your hypothesis include independent and dependent variables?
• Do you have operational definitions?

Naturalistic Observation

• Observe behavior in natural habitats (i.e. home, school, mall)
• Natural settings, but researchers have no control- you don’t know when the event you want to study will actually happen

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Observations

Laboratory Observation

• Observed in laboratory/artificial setting
• Can control aspects of the study.
• You can create a lab anywhere!
• A lab is created any time you alter the natural surrounding.

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Observations

Testing your Hypothesis w/Surveys

Unit 1 Day 5

�Review: What are the 5 steps to the research process?�

• 1.
• 2.
• 3.
• 4.
• 5.
• Bonus: What do you do next?
• Bonus: Which step do surveys go with?

How else can we test our Hypothesis?

• 1.
• 2.
• 3.
• 4.

First: Who is your Target Population?

• Considerations: Age, gender, race, clique, income, location, specific educational requirements
• How do you intend to sample them?
• Random
• Proportional or Stratified
• Where will you hand our your surveys?

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Second: you need good Operational Definitions

• Intelligence, popular, fashionable, attractive, aggressive, interested, dedicated, better driver, honest, distracted
• Ex: distracted while driving: talking, talking on the phone, singing, texting, eating, playing with the radio, reading, putting on make-up, brushing your teeth, looking for something
• Ex: interested in:
• Ex: intelligent:

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Wording your questions

• Open ended vs. forced responses
• Example:
• Wording effect
• Limit vs. censor, welfare example
• Positive vs, negative wording
• Disguising your intent
• 5 questions about your hypothesis, the rest about other things.

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Warnings:

• Generalizing Results
• Study on unhappy wives
• Volunteer Bias
• Honesty & Accurate Introspection

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Begin w/ the End in mind

• How do you intend to organize and analyze your data?
• Throw in a few questions that might pull out some other variables.
• Overly involved kids and bad-grades

Final Questions

• Can a survey tell you scientifically the cause?
• What can a survey show you?