Week one Introduction to Statistics Chs 221 Dr. wajed Hatamleh Chapter 1 Population Sample Variable and parameter Variables Post test Dr. Wajed Hatamleh

What is Statistics? Statistics is the term for a collection of mathematical methods of organizing, summarizing, analyzing, and interpreting information gathered in a study 2

Statistics Data Collection Summarizing Data Interpreting Data Drawing Conclusions from Data

Data Collection Designing experiments Observational studies Does aspirin help reduce the risk of heart attacks? Observational studies Patient attitude toward saudi nurses

Summarizing and Interpreting Data Grade distribution for a college course ( Growth and development course NUR 353)

Drawing Conclusions Quality control and improvement Analysis of designed experiments Analysis of observational studies

Definition Data observations (such as measurements, genders, survey responses) that have been collected Dr. Wajed Hatamleh

Definition Population The complete collection of all elements (scores, people, measurements, and so on) to be studied; the collection is complete in the sense that it includes all subjects to be studied Dr. Wajed Hatamleh

Population Examples Unemployment - Status of ALL employable people (employed, unemployed) in the KSA Entry college Scores - scores of EVERY person that took the Entry college in KSA during 2009 Responses of ALL currently enrolled underage college students as to whether they have consumed Arabic Coffee in the last 24 hours

Sample A subset of the population data that are actually collected in the course of a study.

Sample Examples Unemployment - Status of the 1000 employable people interviewed. College entry Scores - scores of 20 people that took the exam during 2009 Responses of 538 currently enrolled underage college students as to whether they have consumed Arabic coffee in the last 24 hours

Population vs. Sample Population Sample

WHO CARES? In most studies, it is difficult to obtain information from the entire population. We rely on samples to make estimates or inferences related to the population.

Definition population parameter Parameter a numerical measurement describing some characteristic of a population. population parameter Dr. Wajed Hatamleh

Definition sample statistic Statistic a numerical measurement describing some characteristic of a sample. sample statistic Dr. Wajed Hatamleh

Key Terms 1. Population (Universe) 2. Sample 3. Parameter 4. Statistic All Items of Interest 2. Sample Portion of Population 3. Parameter Summary Measure about Population 4. Statistic Summary Measure about Sample P in Population & Parameter S in Sample & Statistic Data facts or information that is relevant or appropriate to a decision maker Population the totality of objects under consideration Sample a portion of the population that is selected for analysis Parameter a summary measure (e.g., mean) that is computed to describe a characteristic of the population Statistic a summary measure (e.g., mean) that is computed to describe a characteristic of the sample

Definition Variable: Is a characteristics of an individual or object, it can be qualitative or quantitative. Examples: (IQ level, Heart rate, age, gender, height, weight, blood pressure, income, eye color, cholesterol level) Dr. Wajed Hatamleh

Qualitative and Quantitative Data( variable) Data can be further classified as being qualitative or quantitative. The statistical analysis that is appropriate depends on whether the data for the variable are qualitative or quantitative. In general, there are more alternatives for statistical analysis when the data are quantitative.

Qualitative Variables ( Data) Labels or names used to identify an attribute of each element Often referred to as categorical data Can be either numeric or nonnumeric Appropriate statistical analyses are rather limited Examples: Gender, eye color,

Quantitative variables (DATA) Quantitative data indicate how many or how much: discrete, if measuring how many continuous, if measuring how much Quantitative data are always numeric. Examples: Height of nursing student, patient weight and age,

Working with Quantitative Data Quantitative data can further be described by distinguishing between discrete and continuous types. Dr. Wajed Hatamleh

Definition Discrete data (i.e. the number of possible values is result when the number of possible values is either a finite number or a ‘countable’ number (i.e. the number of possible values is 0, 1, 2, 3, . . .) Example Number of siblings: 0, 1, 2, etc. (1.2 is not possible) Number of hospital beds (129.03 4 beds is not possible Dr. Wajed Hatamleh

Definition Continuous (numerical) data result from infinitely many possible values that correspond to some continuous scale that covers a range of values without gaps, interruptions, or jumps Example: The amount of milk that a cow produces; e.g. 2.343115 gallons per day, weight, height. Dr. Wajed Hatamleh

Definitions Random Sample members of the population are selected in such a way that each individual member has an equal chance of being selected Dr. Wajed Hatamleh

Sample data must be collected in an appropriate way, such as through a process of random selection. If sample data are not collected in an appropriate way, the data may be so completely useless that no amount of statistical torturing can salvage them. Dr. Wajed Hatamleh

selection so that each has an Random Sampling selection so that each has an equal chance of being selected Dr. Wajed Hatamleh

Systematic Sampling Select some starting point and then select every K th element in the population Dr. Wajed Hatamleh

use results that are easy to get Convenience Sampling use results that are easy to get Dr. Wajed Hatamleh

Post test time Are you ready? Dr. Wajed Hatamleh

A collection of observations. The population is A collection of observations. A collection of methods for planning studies and experiments. The complete collection of all elements. D. A sub-collection of members drawn from a larger group. Dr. Wajed Hatamleh

A collection of observations. The population is A collection of observations. A collection of methods for planning studies and experiments. The complete collection of all elements. D. A sub-collection of members drawn from a larger group. Dr. Wajed Hatamleh

Which is an example of quantitative data? A. Weights of high school students. B. Genders of actors and actresses. C. Colors of the rainbow. D. Consumer ratings of a particular automobile (below average, average, and above average.) Dr. Wajed Hatamleh

Which is an example of quantitative data? A. Weights of high school students. B. Genders of actors and actresses. C. Colors of the rainbow. D. Consumer ratings of a particular automobile (below average, average, and above average.) Dr. Wajed Hatamleh

Which is not an example of continuous data? A. Temperature on a thermometer. B. Number of students in an algebra class. C. Mean weight of 100 flour sacks. D. Amount of water pumped from a pond per day. Dr. Wajed Hatamleh

Which is not an example of continuous data? A. Temperature on a thermometer. B. Number of students in an algebra class. C. Mean weight of 100 flour sacks. D. Amount of water pumped from a pond per day. Dr. Wajed Hatamleh

End of Chapter 1