Cheatography
https://cheatography.com
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 |
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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. |
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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 |
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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? |
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