Data Collection
True or False: An experiment is a study where a researcher observes and watches without changing anything.
False: An experiment is a study where a researcher applies or manipulates something and then observes the results.
True or False: A stratified sample is drawn from a naturally occurring subgroup.
False: A stratified sample is drawn from groups divided by the researcher by similar characteristics.
True or False: A confounding variable is when the experimenter can't tell the difference between the effects of different factors on a variable.
True
What is the first step in designing a statistical study?
Identify the variable of interest
Explain how the following experiment could be biased: You select a single class in a high school at random and ask each student what their favorite subject is.
Potential answers: Does not get information from enough students in the school, kids could be taking certain classes because it is their favorite (ex. it is an elective such as an art class and everyone in there says their favorite subject is art), etc.
True or False: A simulation is the use of a mathematical or physical model to reproduce the conditions of a situation or process.
True
Which sample technique consists only of available members of the population?
Convenience Sample
How are Block and Match Pairs Designs similar/related?
Similar groups of subjects are being studied based on similar characteristics.
Why is it important to develop a detailed plan for collecting data?
You may have different data between participants that isn't comparable or viable. You should make sure each piece of data is the best for your study.
What does it mean to sample without replacement?
Once something/someone is chosen it is not put back into the population.
What method of data collection would you use to collect data for the following: A study in which a researcher observes the number of people littering outside of a school?
Observational Study
Identify the sampling technique: You assign each student a number and, after choosing a starting number, question every 25th student.
Systematic Sample
Two groups are given allergy medications. One group is given the real ones, and the other is given a pill with no effects. The group with the fake pills says that their allergies have gotten better since being on the "medication". What is this called?
Placebo Effect
Why is it important to use Descriptive Statistics Techniques?
If you don't use it, your data may be unorganized or displayed incorrectly.
Which sampling technique is used in the following: Looking at all the people in Wisconsin, then surveying everybody with the zip codes 53168 and 53181 to determine their favorite soda flavor
Cluster Sample
Which method of data collection would you use to collect data for the following: A study of the effect of exercise on relieving depression?
Experiment
Identify an advantage of a Simple Random Sample.
Correct responses may include: Simple/easy, random, unbiased, etc.
What type of experiment is best for being unbiased?
Double-blind
What is the final step of designing a statistical study?
What is it called when subjects change their behavior because they know they are in an experiment?
Hawthorne Effect
What method of data collection would you use to collect data for the following: A study of the success of graduates of a large university in finding a job within one year of graduation?
Which sampling technique is very accurate but also the most time-consuming and difficult to execute?
Census
What three aspects of an experiment are necessary for a well-designed experiment?
Control, Randomization, Replication
How many major steps are there in designing a statistical study?
6
A quality control department is testing 25 smartphones from a shipment of 300 smartphones. Explain how you would use a number table to pick the 25 smartphones.
Start by numbering each phone from 1-300. Go to the given line in the number table, count every 3 digits on that line, and skip every number greater than 300 or any repeats. Do this until you get 25 total numbers.