Deck 10: Data Collection Methods

Question 1

Differentiate between descriptive and inferential statistics.

Answer 1

"Difference between descriptive and inferential statistics"
Descriptive statistics:
Descriptive statistics describe, organize, and summarize data. Descriptive statistics consist of "measures of central tendency and measures of dispersion." Measures of central tendency are descriptive statistics that illustrate the location center of a distribution of data. A distribution consists of scores, numerical values, and their frequency of occurrence.
"Measures of dispersion" (descriptive statistics), which represent the spread and variability among a place of numerical data.
Inferential statistics:
Inferential statistics focus on the course of action of selecting a sample and using the information to generalize to a population. Information contained in sample is used t o make inferences concerning a parameter.

Question 2

Compare and contrast the three measures of central tendency.

Answer 2

"Compare and contrast the three measure of central tendency"
• "Mean
• Median
• Mode"
Mean:
A measure of central tendency calculated by summing a group of scores and dividing the sum by total number of scores also called as average.
Median:
A measure of central tendency that signifies the middle score in distribution
Mode :
The score that occurs often in a distribution; a measure of central tendency used most often with nominal level data.
Level measurement:
The use of mean is appropriate with interval and sometimes-ordinal data. The mean is a precise measure than median or mode because it takes into account every score in distribution. The mean is also the most stable of three measures.
If a number of samples are randomly drawn from a target population, the mean varies less, compared with the median and mode. The median is an ordinal statistic based on ranks.
Shape of distribution:
The shape of distribution is another factor that influences the researcher's choice of measure of central tendency. In skewed distributions " the mean, median, and mode" do not coincide, although their relative positions remain constant in moving away from the peak toward the tail.
The order is always from mode, to median, to mean. In a skewed distribution, the median always falls somewhere between the mean and mode.
This characteristic makes the median the most suitable measure of central tendency for describing a skewed distribution.
Research objective:
The researcher uses the mode as a preliminary indicator of central tendency. If a more precise measure of central tendency is warranted, the median or mean is used. To describe a skewed distribution, the researcher chooses the median to give a balanced picture of the extreme scores or outliers.
In addition, the median is sometimes employing as a point in distribution at which scores can be divided into two kinds containing the same number of respondents.
The mean is preferred over the median because the mean is easily used in more advance d statistical analyses.

Question 3

Compare and contrast the three measures of dispersion.

Answer 3

Compare and contrast the three measure of dispersion:
The three measure of dispersion are as follows:
• "Range
• Variance
• Standard deviation"
Range:
A measure of variability that is the variation between the lowest and highest value in distribution
Variance:
Measure of variability, which is the average squared deviation from mean
Standard deviation:
The most frequently used measure of variability; the distance score varies from the mean.
The range, quick and simple to obtain, is not very reliable. Although the range is calculated from two scores in a distribution, both the "variance and standard deviation" "take into account every score in a distribution.
Despite its relative stability, the variance is not widely used because it cannot be employed in m any statistical analyses.
In contrast, Standard deviation squares the deviated scores and returns them to their original units of measure. Calculating the Standard deviation is the preliminary step for obtaining other statistical measures, particularly in context of statistical decision-making.

Question 4

Distinguish between parametric and nonparametric procedures.

Question 5

Evaluate a researcher's choice of descriptive and inferential statistics in published research.