Research Methods

A series of steps that people use to solve problems The Scientific Method A series of steps that people use to solve problems STEPS: State the problem Form a hypothesis* Perform an experiment Record and analyze data Draw a conclusion * Not always necessary for solving every problem

Two Types of Scientific Investigations: (1) Controlled Experiments Performed in order to determine if a variable affects something else Two or more groups of subjects, treated exactly the same One exception: One group does NOT get the variable in question (control group) The other group(s) is/are called the experimental group(s)

Example: Does CortiSlim really help people lose weight? No, it doesn’t! [Does CortiSlim affect weight?] Group 1 Experimental Group Group 2 Control Group Takes CortiSlim No CortiSlim PLACEBO Treated the same in all other ways! Compare weight loss after 6 months (?) Average wt. loss: 1 lb. Average Wt. Loss: 1 lb.

Compare average IQ between the groups (2) Studies Performed when controlled experiments are not possible (because a control group is not possible) Example: Does gender affect IQ? Average IQ: 100 Average IQ: 120 Group 1 Males Group 2 Females Compare average IQ between the groups Fake Data

Controlled Experiment or Study? Controlled Exeriment or Study? Does light intensity affect plant growth? Does body weight affect blood pressure? Does age affect physical strength? Does the amount of TV watched affect how well a child sleeps? Does walking your dog increase its lifespan? Does the brand of skin cream you use affect how young your skin looks? Does height affect heart attack rate?

Conduct a Controlled Experiment Conduct a Controlled Experiment!!! Question: Does squeezing a stress ball really work to reduce your stress level? Materials Provided: stress balls, clock with second hand How will you measure “stress level”? What will your control group consist of? Which variables should stay constant? What is your hypothesis?

Procedures Divide class into two groups: experimental and control. Experimental subjects get a stress ball; control group does not. Everyone take heart rate (count for 30 sec. X 2); record. Experimental group relaxes while squeezing stress ball for two minutes, during which time the control group just relaxes. Re-take heart rate (step #3); record. Gather class data and calculate averages. Analyze class data and draw a conclusion.

Stress Ball Experiment: CLASS DATA HR (beats/min.) EXPERIMENTAL GROUP HR (beats/min.) CONTROL GROUP Before After jAveragek lWhat happened?m

LABORATORY REPORT FORMAT Your Name Date Name of Partner(s) Title of Lab Problem Statement State the problem your experiment aims to answer “In this experiment we will determine...” or “How does (x) affect (y)?” Identify the independent variable (x) and the dependent variable (y) of your experiment Include a hypothesis using an “If….then…..because….” statement Procedures Carefully explain the steps needed to replicate your experiment. Clarify any control group in your procedures. We use a control group to compare our results in order to determine whether or not there was a change or difference in the data. The control group is usually the group or setup within the experiment that has nothing added or done to it. Data Display data in the form of a table and a graph, each properly titled and labeled Indicate units of measurement (if appropriate) Conclusions Referring to your data, answer your problem statement. Discuss at least three important issues that affected the accuracy or truthfulness of your results LABORATORY REPORT FORMAT

Conduct a Controlled Experiment Conduct a Controlled Experiment!!! Question: Materials Provided: stress balls, clock with second hand, stopwatches How will we measure “stress level”? What will our control group consist of? Which variables should stay constant? What is your hypothesis?