Low-cal dog food A dog food company wants to compare a new lower calorie food with their standard dog food to see if its effective in helping inactive dogs maintain a healthy weight. They have found several dog owners willing to participate in the trial. The dogs have been classified as small, medium, or large breeds, and the company will supply some owners of each size of dog with one of the two foods. The owners have agreed not to feed their dogs anything else for a period of 6 months, after which the dogs weights will be checked. a) Identify the treatments, the experimental units, and the response variable. b) Describe a method of assigning treatments if this is to be a randomized block design with size of the breed as the blocking variable. c) Is blinding important in this experiment? Doubleblinding? How could blinding be conducted?
th ST 260 Aug. 28 Notes: Population, Sample, Types of Data Difference in Population vs Sample: Population → Measured by Census → Measures are called “Real Parameters” Sample → Smaller Group, Subset of Population → Serves to Estimate the Parameter o Population: collection of all items of interest in a study o Sample: subset collected to be a representative of population Should characteristics of each sample be expected to be the same as each other (in the sample) No. Should characteristics of a sample be the same as the population No. BUT, close. Data Sources for Statistics: Existing Sources- data that is already there Observational Study- example: traffic counts Experiments Descriptive vs Inferent