Term
| What are the two basic ways to gather data? |
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Definition
| observational study and experiment |
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Term
| _____attempt to manipulate or influence the subjects in order to obtain data. |
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Definition
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Term
| When doing_____, subjects can be randomly assigned to groups. |
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Definition
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Term
| _____simply measure charactersitics of the subjects without attempting to manipulate or influence the subjects. |
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Definition
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Term
| ____can prove causation. ____can only say that the variables are related to each other. |
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Definition
| experiments; observational studies |
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Term
| In ______, subjects cannot be randomly assigned to groups. |
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Definition
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Term
| What are the advantages of using an experiment? |
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Definition
| you can prove causation and apply randomization |
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Term
| What are the advantages of using an observational study? |
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Definition
| you can only prove association of two variables and not causation |
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Term
| A_____attempts to take a cross section of the population at the current time. |
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Definition
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Term
| A survey that asks "who is your favorite singer?" would be an example of a _____. |
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Definition
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Term
| A _____collects information about prior exposures, habits, and behaviors. In other words, it "looks backwards" |
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Definition
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Term
| A survey asking adults how many pets they had when they were in high school would be an example of ______. |
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Definition
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Term
| A_____recruits subjects into a study and then collects information on future behavior and results by following the subjects forward in time. In other words, it "looks forward". |
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Definition
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Term
| A study wishes to examine "how many hours a week do you watch television?" Subjects are recruited into the study and then followed for a year to record viewing habits. This would be an example of ______. |
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Definition
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Term
| A _____is a specific type of retrospective study in which subjects who have a response outcome of interest and subjects who the other response outcome are compared on an explantory variable. |
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Definition
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Term
| A study to see if there is an association between cell phone usage and brain cancer. WE can form a sample of subjects with brain cancer and a sample of subjects without brain cancer and compare the past use of cell phones for both groups. This would be an example of a _____. |
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Definition
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Term
| _____occurs from using nonrandom samples or not using large enough sample frame (undercoverage). |
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Definition
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Term
| In an election poll, if we just took the first 30 people that walked up to us, rather than ranodmly selecting people to poll, this might result in _____. |
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Definition
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Term
| In an election poll, if we just took samples at a few of the voting stations and did not sample from all of them, this would be_____. |
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Definition
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Term
| _____occurs when some sampled subjects cannot be reached or refuse to participate or fail to answer some questions. |
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Definition
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Term
| If we send out 500 surveys and only get 22 back, this could results in ______. These 22 dont give a large enough sample size and might not be reprsentative of the population. |
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Definition
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Term
| _____occurs when the subject gives an incorrect response , or the wording of the question is confusing/misleading, or the way the interviewer asks the question is confusing/misleadingor encourages the respondent to favor a particular answer. |
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Definition
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Term
| Asking the question on a survey this way might result in _____: "please vote for one of the following candidates" CANDIDATE A or candidate b |
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Definition
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Term
| A _____is a controlled study in which one or more treatments are applied to experimental units. The experimenter then observes the effect of varying these treatments on a response variable. |
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Definition
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Term
| The ______is the person, object, or some other well-defined item upon which a treatment is applied. Another word for this is subject. |
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Definition
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Term
| The _____is a condition applied to the experimental unit. (i.e. a new drug is administered to patients) |
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Definition
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Term
| The _____is a quantitative or categorical variable that represents our variable of interest. |
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Definition
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Term
| What is the goal in an experiment? |
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Definition
| to determine the effect the treatment has on the response variable |
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Term
| An experiment is _____if neither the experimental unit nor the experimenter knows what treatment is being given to the experimental unit. |
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Definition
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Term
| In a ______, the experimental units are randomly assigned to the treatments. |
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Definition
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Term
| A _____is one in which the experimental units are somehow related or matched before the experiment takes place. For example: the same person before and after a treatment, twins, husband, and wife, etc. |
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Definition
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Term
| An experiment where subjects could take one treatment the first time and get a headache, and the other treatment the second time they get a headache. What type of design is this? What is the response variable? |
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Definition
| cross over design; the response variable is whether the subject's pain is relieved |
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Term
| In matched pairs experiments, a set of matched experimental units is referred to as a _____. |
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Definition
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Term
| A block design with random assignment of treatments to units within blocks is called a _____. |
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Definition
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Term
| If we randomly select 5 scores from Test 1 and then randomly select 5 scores from Test 2, we will have _____. |
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Definition
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Term
| If we randomly select 5 students and look at their scores on Test 1 and Test 2, then we will have ______. This is equivalent to using an experiment with a matched pairs design. |
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Definition
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Term
| Often you will see u1-u2 written as ____, which just stands for the difference between the two means. |
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Definition
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Term
| What assumptions must be met when creating a significance test for two means? |
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Definition
| randomly sample; normally distributed |
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Term
| Dependents samples use _____ |
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Definition
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Term
| Let's say you have two groups but there are different sample sizes in the groups. Are these independent or dependent samples? |
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Definition
| independent because there are different sample sizes in the two groups |
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Term
| IF tehre is a significant difference between our sample means, do we reject or not reject the null hypothesis? |
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Definition
| reject the null hypothesis |
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Term
| If there is not a significant difference between our sample means, would we reject or not reject the null hypothesis? |
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Definition
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Term
| IF 0 is in the interval, can we reject the null hypothesis? |
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Definition
| no we cannot reject the null hypothesis |
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Term
| IF 0 were not on the interval, then would we reject the null hypothesis? |
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Definition
| yes we could reject the null hypothesis |
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Term
| When doing significant tests for two proportions, what assumptions must be met? |
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Definition
| categorical response variable, independent random samples, the sample sizes are large enough so that there are at least five "successes" and five "failures" in each group |
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Term
| When calculating confidence intervals for proportions, if 0 is on our confidence interval then there may be zero difference between the proportions so can we reject the null hypothesis? |
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Definition
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Term
| If the interval does not contain zero, do we reject or not reject the null hypothesis? |
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Definition
| reject the null hypothesis |
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Term
| IF 0 falls in the confidence interval, it is plausible that the two population proportions are equal. so should we reject or not reject the null hypothesis? |
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Definition
| not reject the null hypothesis |
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Term
| What two assumptions must be met when you are doing a Goodness of Fit test? |
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Definition
| the sample must be random and the expected counts must all be at least five |
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Term
| A survey that asks: who is your current favorite singer? would be an example of what type of study |
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Definition
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Term
| a survey that asks adults how many pets they had when they were in high school would be an example of what type of study? |
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Definition
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Term
| A survey that asks "how many hours a week do you watch television?" would be an example of what type of study? |
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Definition
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Term
| the person, object, or some well defined item upon which a treatment is applied |
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Definition
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Term
| a condition applied to the experimental unit |
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Definition
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Term
| a quantitative or categorical variable that represents our variable of interest |
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Definition
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