DescriptiveStatistics is the branch of statistics thatsummarizes data after being collected. It represents a sample of population, ormay represent it all. It is used for students to summarize their grades to aform known as GPA, an average of the student’s grade points. DescriptiveStatistics is limited, as you can do summation and subtraction aboutsamples you have already collected, for an example, if a doctor used a newmedicine for cancer, and worked with his patients, he can’t say that it is surethat it works with all the patients.
Inferential statistics can make sure ifthe medicine is good for everyone or not.Descriptivestatistics consists of four major types, they are frequency measurement,central tendency measurement, dispersion and variation measurement, andposition measurement. The frequency measurement shows how often the thingsoccurs, central tendency measurement shows the distribution by various points, dispersionand variation measurement shows the spread of scores by showing intervals,position measurement shows how scores fall in relation to other.Descriptivestatistics can determine many types of variables like, nominal measurement,ordinal measurement, interval measurement, ratio measurement. The nominalmeasurement is simply a qualitative measurement not quantitative measurement.
The number in this measurement is a name or label, if two labels have the samenumbers, they can be in the same category. There is no smaller than or greaterthan relations between the numbers it is labels. As an example, theinternational code of the telephone numbers of a country, the numbers ofbusses. In other words, it can be called categorical variables. The ordinalmeasurement is rank variables. In this measurement we can use operationslike subtraction, addition, equalities, and inequalities. Relations likegreater than or smaller than can be used in this type of measurements.
As anexample, the horse races can be surveyed as who reached the end first and whois the second, etc. The interval measurement is also rank variables, butthe ratios between the numbers are not meaningful. Differences are meaningful.Scales of variables measurement are referred to interval measurement. Latterusage of this measurement is not recommended.
The ratio measurement isthe most type used for qualitative measurements. Numbers are everything in the meaning,as ratios are taken from it. As an example, temperature, mass, length are measuredby it, as they are compared to the absolute zero.Descriptive statisticsis very important and useful in many fields of life, as it can summarize the datacollected in a meaningful way. The data summarized then can be used in work in asimple way without calculations again.