The average or the arithmetic mean is defined as the sum of all measurements divided by the number of observations. For example, the average of the numbers 10, 12 and 22 is 14.6 because 10+12+22=44 and there are three observations, so 44 divided by three is 14.6. When there are only numbers involved, an average problem is quite simple.
2. Name the two concepts of average?
★ Moden
★ Median
3. List some topics which are include in data analysis?
There are many data analysis topics that you should be familiar with. Many of them are described here. They include:
★ Averages
★ Box Plots
★ Normal Distributions
★ Counting Methods - Sets
The median of a set of numbers is the number that is exactly half way between the largest and smallest number, when the numbers are arranged from smallest to largest.
5. Please tell me what is a box plot?
A box plot graphically displays groups of numerical data through their five-number summaries: the smallest observation (sample minimum), lower quartile (Q1), median (M), upper quartile (Q2) and largest observation (sample maximum).
The box plot is often called a "whisker" plot because "whiskers" extend outward from the boxes to the least and greatest values.
6. List the properties which are satisfied by the normal distributions?
All normal distributions satisfy the following properties:
★ Approximately 68% of the observations fall within 1 standard deviation of the mean
★ Approximately 95% of the observations fall within 2 standard deviations of the mean
★ The mean, median and mode of the data are nearly all equal
7. Define inclusion-exclusion principle in data analysis?
A counting principle that you may appear on a data analysis question is the inclusion-exclusion principle, which states that the number of elements in the union of two finite sets equals the count of the members in the two sets minus the number of elements in the intersection of the two sets. The number of elements in a set is denoted using two parallel lines, ||. Using set notation, the inclusion-exclusion principle for sets D and E is written as the following:
|D∪E| = |D| + |E| - |D∩E|
8. Do you know what is data analysis?
Data analysis is the process of systematically applying statistical and/or logical techniques to describe and illustrate, condense and recap and evaluate data.
9. What is mode in data analysis?
The mode of a set of numbers is the number that appears most often.
10. What is quartile in data analysis?
The quartiles of a set of values are the three points that divide the data set into four equal groups, each representing a fourth of the population being sampled.
11. What you know about interquartile range as data analyst?
A measure of the dispersion of the data that is shown in a box plot is called the interquartile range. It is the difference between the upper quartile and the lower quartile.
12. Define normal distribution in data analysis?
The normal distribution is a pattern for the distribution of data which follows a bell-shaped curve. The normal distribution is called normal because the data points are concentrated in the center near the mean. The data does not usually contain extreme values and the probability of deviations of the data points from the mean are (nearly) identical in either direction.
13. What is set in data analysis?
A set is a collection of distinct objects that have a specific property.
For example, the set of all digits greater than 5 includes the numbers 6, 7, 8 and 9.
14. List the objects of set in data analysis?
There are two objects of set:
★ Members
★ Elements
15. What is empty set in data analysis?
A set that contains no members is called the empty set and is denoted with the symbol '∅'.
16. Name two operations to perform sets in data analysis?
Two operations to perform sets are:
★ Intersection
★ Union
17. What is disjoint set in data analysis?
If two sets have no members in common then the two sets are called disjoint set.
18. What is a venn diagram in data analysis?
A Venn Diagram is one way that sets can be visualized.
19. What is the purpose of the data analysis and interpretation phase?
The purpose of the data analysis and interpretation phase is to transform the data collected into credible evidence about the development of the intervention and its performance.
20. List some steps which are included in data analysis and interpretation process?
This process usually includes the following steps:
★ Organizing the data for analysis (data preparation)
★ Describing the data
★ Interpreting the data (assessing the findings against the adopted evaluation criteria)
21. What does a quantitative data do in data analysis?
Where quantitative data have been collected, statistical analysis can help measure the degree of change that has taken place and allow an assessment to be made about the consistency of data.
22. List the evaluation criteria as the basis for organizing and analyzing data?
★ Relevance
★ Results/Impact
★ Sustainability
★ Effectiveness
★ Efficiency
23. Explain the difference between association, causation and confounding?
One of the most important issues in interpreting research findings is understanding how outcomes relate to the intervention that is being evaluated. This involves making the distinction between association and causation and the role that can be played by confounding factors in skewing the evidence.
24. Define association in data analysis with example?
An association exists when one event is more likely to occur because another event has taken place. However, although the two events may be associated. One does not necessarily cause the other. The second event can still occur independently of the first.
Example:
Some research supports an association between certain patterns of drinking and the incidence of violence. However, even though harmful drinking and violent behavior may co-occur, there is no evidence showing that it is drinking that causes violence.
25. Define causation with example?
A causal relationship exists when one event (cause) is necessary for a second event (effect) to occur. The order in which the two occur is also critical.
Example:
★ For intoxication to occur, there must be heavy drinking, which precedes intoxication.
★ Determining cause and effect is an important function of evaluation, but it is also a major challenge.
Causation can be complex:
★ Some causes may be necessary for an effect to be observed, but may not be sufficient; other factors may also be needed.
★ While one cause may result in a particular outcome, other causes may have the same effect.
Being able to correctly attribute causation is critical, particularly when conducting an evaluation and interpreting the findings.
