PsychStat

Statistics

is a science that deals with the collection, presentation, analysis, and interpretation of data for wise decision-making.

data - collection, presentation, analysis, interpretation - decision

Statistics

collection of data
organization and presentation of data
analysis of data
interpretation of data

four essential process in statistics

collection of data

refers to the gathering of related information

(a) what is useful and needed
(b) where to get the information
(c) how to get the information

related information (collection of data)

organization and presentation of data

refers to the systematic way of organizing data

(a) collecting
(b) classifying and arraying
(c) presenting data gathered in preparation to its analysis.

organization and presentation of data involves

analysis of data

refers to extracting relevant information from the data at hand

(a) comparison and contrast
(b) description
(c) statistical measurements

analysis of data involves

interpretation of data

refers to drawing of logical statements from the analyzed information

(a) generalizing
(b) forecasting
(c)recommending solutions and interventions

interpretation of data involves

Psychology is science that deals with the study of human behavior and cognition or mental process. This definition is the product of the rigid activities resulted from natural observation and scientific exposure and interactions of the early philosophers and psychologist who untiringly look for explanations, reasons, causes and effects on what, why and how nature and nurture affect individuals.

historical roots of psychology statistics

Socrates

Plato

Aristotle

Dr. Nevil Maskelyne

Friedrich Bessel

Gustav Theodor Fechner

Hermann von Helmholtz

Charles Darwin

Franciscus Cornelis Donders

Wilhelm Wundt

Granville Stanley Hall

William James

James McKeen Cattell

Edward Bradford Titchener

Francis Galton

Hermann Ebbinghaus

Franz Anton Mesmer

James Braid

Sigmund Freud

philosophers and psychologist

Psychology like other scientific field has general goals that guide its investigation about human nature.

importance of statistics in psychology

1. To describe the different ways of how people behave. It is the accurate and detailed record of behavioral observations. (to describe)

2. To explain the various causes of why certain processes and behavior occurs. (to explain causes)

3. To predict and determine how the organism will behave in a certain situation. (to predict)

4. To control or change an organism’s behavior and mental processes by learning how to modify or alter undesirable behavior. (to change)

These main goals of psychology are the following

Descriptive Statistics
Inferential Statistics

Division of Statistics

Descriptive Statistics

is the totality of methods and treatments employed in the collection, description, and analysis of numerical data.

is to tell something about the particular group of observation

The purpose of descriptive statistics

Inferential Statistics

is the logical process from sample analysis to a generalization or conclusion about a population.

statistical inference or inductive statistics

Inferential Statistics also called

Population

consists of all the members of the group about which you want to draw a conclusion

Sample

a portion, or part of the population of interest selected for analysis.

Parametric

is a numerical index describing a characteristic of a population

Statistic

is a numerical index describing a characteristic of a sample

primary data
secondary data

sources of data

Primary Data

are data that come from the original source, and are intended to answer specific research questions.

Interview
Mail-in questionnaire
Survey
Experimentation

examples of primary data

Secondary Data

are data that are taken from previously recorded data.

Information in Research
Conducted Industry
Financial Statement
Business Periodical
Government Reports

examples of secondary data

Constant

characteristic of objects, people, or events that does not vary.

Boiling Point
6th Month in a Calendar

examples of constant

Variable

characteristic of objects, people, or events that can take of different values

Eye color
Age
Civil Status

examples of variable

qualitative data
quantitative data

Types of Data

Qualitative Data

are data that can be described as LETTERS or SYMBOLS

Sex
Religious Preferences
Civil Status

examples of Qualitative Data

Quantitative Data

are data that can be described as NUMBERS or QUANTITY. It can be DISCRETE or CONTINUOUS.

Age
Salary
Test Scores

examples of Quantitative Data

Experimental
Mathematical

Classification of Data

Independent Variables
Dependent Variables

Experimental Variables

Independent Variables

are variables controlled by the experimenter/ researcher, and expected to have an effect on the behavior of the subjects. Variable that is manipulated.

Dependent Variables

Is some measure of the behavior of subjects and expected to be influenced by the independent variable. Variable that changes as a result of the manipulation of the independent variable.

Continuous Variables
Discrete Variables

Mathematical Variables

Continuous Variable

is variable which can assume any of an infinite number of values, and can be associated with points on a _____ line interval

Discrete Variable

is variable which consist of either a finite number of values or countable number of values.

Nominal
Ordinal
Interval
Ratio

Levels of Measurements

Nominal

is mutually exclusive and exhaustive meaning it is used to differentiate classes or categories for purely classification or identification purposes

Nominal

It is the weakest form of measurement because no attempt can be made to account for differences within the particular category or to specify any ordering or direction across the various categories. It is also discrete variable.

Gender – Male, Female
Agreement – Yes, No

examples of nominal

Ordinal

is used in ranking.

Ordinal

It is somewhat stronger form of measurement, because an observed value classified into one category is said to posses more of a property being scaled than does an observed value classified into another category. It can be discrete variables.

Satisfaction – Unsatisfied, Neutral, Satisfied, Very Satisfied

examples of ordinal

Interval

is used to classify order and differentiate between classes or categories in terms of degrees of differences.

Interval

has NO TRUE ZERO. It is either discrete or continuous.

Temperature
Calendar
IQ

examples of interval

Ratio

It differs from interval measurement only in one aspect; it has TRUE ZERO POINT. It can be discrete or continuous variable.

Weight
Age
Salary

examples of ratio

Indicates a distinction

Nominal Characteristics of Levels of Measurement (properties)

Indicates distinction
Indicates the direction of the distinction

Ordinal Characteristics of Levels of Measurement (properties)

Indicates distinction
Indicates the direction of the distinction
Indicates the amount of distinction

Interval Characteristics of Levels of Measurement (properties)

Indicates distinction
Indicates the direction of the distinction
Indicates the amount of distinction
Indicates an absolute zero

Ratio Characteristics of Levels of Measurement (properties)