A Note on Statistics
Lecture Notes: Statistics A note on basic statistics
Statistics is the practice or science of collecting and analyzing numerical data in large quantities. So there are two parts1. Collection of Data 2. Analysis of Data- understanding what the data says. Steps in Statistics To carry out any statistical operation, the following steps need to be followed, in the given order: 1. 2. 3. 4. 5. 6. Sampling Estimation Hypothesis Generation Testing Regression Prediction
Collection of Data: Sampling Sampling is the process of selecting some limited number of data from the entire possible population of such data. Selecting 10 apples from all the possible apples in the Universe is an example of sampling. Sample is a set of values (numerical or Boolean- Yes or No) that is taken for a particular question.
The number of items (10 apples in this case) selected is known as the Sample Size. It is believed that the sample size represents the entire universe. Convention is something that is commonly followed and is an unwritten rule within a discipline of study. In statistics convention, n represents the size of sample. Selecting is never easy- be it selecting ONE wife from all the eligible women in the world or selecting a random sample. Random basically means without using a person’s brain. Just select. So, we make a lot of mistakes (or errors) in selecting (or sampling).
Errors in Sampling: Systematic Error
These errors are also known as Non-Sampling Errors. Systematic errors result from decisions that bias the sample selection or response to survey. Bias Bias is an inclination of outlook to present or hold a partial perspective at the expense of (possibly equally valid) alternatives. Response to Survey is the answer given by a person while answering a survey. Four common mistakes that lead to systematic error are: 1. Population Specification Error: This error is one of not understanding who you should be surveying. For Example: If you want to know what people from
Statistics is the practice or science of collecting and analyzing numerical data in large quantities. So there are two parts1. Collection of Data 2. Analysis of Data- understanding what the data says. Steps in Statistics To carry out any statistical operation, the following steps need to be followed, in the given order: 1. 2. 3. 4. 5. 6. Sampling Estimation Hypothesis Generation Testing Regression Prediction
Collection of Data: Sampling Sampling is the process of selecting some limited number of data from the entire possible population of such data. Selecting 10 apples from all the possible apples in the Universe is an example of sampling. Sample is a set of values (numerical or Boolean- Yes or No) that is taken for a particular question.
The number of items (10 apples in this case) selected is known as the Sample Size. It is believed that the sample size represents the entire universe. Convention is something that is commonly followed and is an unwritten rule within a discipline of study. In statistics convention, n represents the size of sample. Selecting is never easy- be it selecting ONE wife from all the eligible women in the world or selecting a random sample. Random basically means without using a person’s brain. Just select. So, we make a lot of mistakes (or errors) in selecting (or sampling).
Errors in Sampling: Systematic Error
These errors are also known as Non-Sampling Errors. Systematic errors result from decisions that bias the sample selection or response to survey. Bias Bias is an inclination of outlook to present or hold a partial perspective at the expense of (possibly equally valid) alternatives. Response to Survey is the answer given by a person while answering a survey. Four common mistakes that lead to systematic error are: 1. Population Specification Error: This error is one of not understanding who you should be surveying. For Example: If you want to know what people from