Cheatography

# 4U Data Management Cheat Sheet (DRAFT) by briivanderlee

A cheat sheet to prepare for the MDM4UC exam.

This is a draft cheat sheet. It is a work in progress and is not finished yet.

### Data

 A collection of inform­ation; a result of observ­ation, measur­ement or experi­ment. It may consist of words, numbers or images.

### What is a variable?

 Any charac­ter­istic of the population being studied or observed.

### Qualit­ative and Quanti­tative Data

 Qualit­ative data is repres­ented using numbers Quanti­tative data cannot be measured

### Discrete and Continuous Variables

 Discrete variables is the result of a count and is only repres­ented using whole numbers Continuous variables are measured and can take on any value

### Components of a Reliab­ility Assessment

 Author's creden­tials The reason the data was collected How the data was collected How up-to-date the data is Other expert opinions

### Sample vs Population

 A sample is the part of the population that is observed or measured. The population is the entire group you want to know about in a study

### Types of Samples

 A simple random sample requires that every selection is equally likely to be selected, and every combin­ation of selections is equally likely of being selected A systematic random sample has a random starting point. Every nth number is selected for inclusion in the sample A stratified random sample requires that data be divided into groups and a random sample from each group is taken A cluster random sample requires that the data be divided into groups. A random sample of the groups is selected, and each member of the selected groups are chosen for the sample. A multi-­stage random sample requires the population be divided into groups. Then, a random sample of groups is chosen, then a random sample of members from each group is selected. A conven­ience sample is a sample that is used because it is conven­ient. A voluntary random sample is any sample that is made by making a general appeal for partic­ipants.

### Types of Questions

 An open question allows the respondent to answer in their own words A closed question requires the respondent to choose from a given list of altern­atives An inform­ation question is a type of closed question used to collect objective data about a subject A rating question is a type of closed question that requires the respondent to rate something according to a scale A ranking question is a type of closed question that requires the respondent to sort a list of altern­atives into their preferred order A checklist question is a type of closed question that gives the respondent a list of altern­atives a list of altern­atives and allows them to choose as many or few as they like

### Types of Bias

 A sampling bias is when the sample chosen does not accurately represent the entire population Non-re­sponse bias occurs when the results are influenced because some of the surveys are not returned at all, or all of the questions are not answered Household bias occurs when one type of respondent is over-r­epr­esented because groups of different sizes are surveyed equally, so that the smaller group gets more repres­ent­atives in the sample than they should Response bias occurs when factors in the sampling influence the result

### Bias Assessment Components

 What is the sample size? What method was used to collect data? Who funded the study?