Sampling types
Every experimental unit have their name put in a hat. Thirty of the names are drawn be included in the experiment. This is an example of _________ sampling.
What is simple random sampling?
Selecting members of the population that are easily accessible will result in this type of bias.
What is selection bias?
Observational study or experiment? An ecology class used binoculars to watch 23 turtles at Lowell Ponds. It was found that 18 were box turtles, and five were snapping turtles.
What is observational study?
Melanie bakes two identical batches of cookies from a recipe, except one batch is made with sugar and the other batch is made with a sugar substitute. She puts the two batches of cookies into identical jars labeled “A” and “B.” She invites her friends to sample each type of cookie and to choose which cookie tastes best. Is this design an example of single-blind or double-blind?
What is single-blind?
Suppose a consumer group wants to test 12 cake pans to see which works the best (bakes evenly). It will test aluminum, glass, and plastic pans in both gas and electric ovens. The experimental units are _______.
What is the 12 cake pans?
The students in 5th period statistics are line up in front of the room. The teacher picked a random starting point. Every 5th student was picked after that. This is an example of _________ sampling.
What is systematic sampling?
Call-in radio shows that solicit audience participation in surveys on controversial topics (abortion, affirmative action, gun control, etc.) are examples of __________ bias.
What is voluntary response bias?
Pick the best method of data collection (observational study, experiment or survey): A study of the effects of eating oatmeal on lowering blood pressure. Group A would eat oatmeal and group B would not eat the oatmeal. Each groups blood pressure measurements would be compared.
What is an experiment?
When subjects in both the treatment and control group exhibit favorable responses, the control group is likely showing ___________.
What is placebo effect?
Suppose a consumer group wants to test 12 cake pans to see which works the best (bakes evenly). It will test aluminum, glass, and plastic pans in both gas and electric ovens. The factors are _______.
What is cake pans and types of ovens?
The employees of a company are split into two groups, men and woman. In each of the groups 100 individuals are chosen at random to ask about their recent raise. This is an example of _______ sampling.
What is stratified sampling?
An experiment used random assignment on a non-random sample of 50 college students to see if there is a relationship between how many credit hours one is taking and the amount of sleep they get.
Can a causal relationship be determined and who can the result be applied to?
A causal relationship can be determined since random assignment is used.
The causal relationship can only be applied to those in the sample.
A college counselor would like to select a simple random sample of all 525 students in the college. She uses the numbers from 001 to 525 to number the students in a college database and then uses a random number table to choose her sample of 30. What numbers correspond to the first 3 students chosen? 06385 61327 51790 63618 23145 46124 20031
What are 063, 132, 182?
A recent study showed that tea drinkers have lower stress levels than coffee drinkers. Tea drinkers are known to have a higher proportion of yoga practitioners than coffee drinkers, and they exercise on average two hours per week more than their coffee-drinking counterparts. The term used to describe these additional factors is _____________.
What is confounding variables?
Suppose a consumer group wants to test 12 cake pans to see which works the best (bakes evenly). It will test aluminum, glass, and plastic pans in both gas and electric ovens. The levels are _______ and the number of treatments are ___.
What is 3 types of pans (aluminum, glass and plastic) and 2 types of ovens (gas and electric)? and What is 6?
After a hurricane, a disaster area is divided into 200 equals grids. Thirty of the grids are selected, and every occupied household in the grid is interviewed to help focus relief efforts on what residents require the most. This is an example of _________ sampling.
What is cluster sampling?
A survey question was asked - "Why is drinking milk good for you?" Pick whether this question would lead to an overestimate or underestimate of the approval rate of milk?
What is overestimate?
__________ reduces bias by spreading any uncontrolled confounding variables evenly throughout the treatment groups.
What is randomization?
A farm-product manufacturer wants to determine if the yield of a crop is different when the soil is treated with three different types of fertilizers. Fifteen similar plots of land are planted with the same type of seed but are fertilized differently. At the end of the growing season, the mean yield from the sample plots is compared. The experimental units are __________.
What is plots of land?
Suppose a consumer group wants to test 12 cake pans to see which works the best (bakes evenly). It will test aluminum, glass, and plastic pans in both gas and electric ovens. The response variable is _______.
What is how evenly the cakes bake?
Define simple random sample.
Every individual has the same probability of being in any of the groups.
Bias often occurs when the survey sample does not accurately represent the population. The bias that results from an unrepresentative sample is called _______.
What is selection bias? Undercoverage, non-response or voluntary bias can occur
If an experiment has __________, then you are able to determine if the explanatory variable has a causational relationship with the response variable.
What is random assignment?
A farm-product manufacturer wants to determine if the yield of a crop is different when the soil is treated with three different types of fertilizers. Fifteen similar plots of land are planted with the same type of seed but are fertilized differently. At the end of the growing season, the mean yield from the sample plots is compared. The explanatory variables are _______.
What is types of fertilizers?
Suppose that the manufacturer wants to test a new fertilizer against the current one on the market. Ten 2-acre plots of land scattered throughout the county are used. Each plot is subdivided into two subplots, one of which is treated with the current fertilizer, and the other with the new fertilizer. Wheat is planted and the crop yields are measured. This design is _________ design.
What is matched pairs?