INTRODUCTION AND BASIC CONCEPTS OF STATISTICS Flashcards
It is the science that deals with data about the condition of a state or community. It is the organization, analysis, and interpretation of data in pursuit of truth.
Statistics
Statistics came from the Latin word _____ meaning state.
status
10 Uses of Stats in our Daily Life
Predictions Testing Forecasts Preparedness Predicting Political Insurance Consumer Financial Sports
2 Branches of Stats
Descriptive Statistics
Inferential Statistics
This branch of statistics makes a group of scores comprehensible. It describes the important characteristics of sample data and predict ones Y score based on the X score.
Descriptive Statistics
It is the branch of statistics that draws conclusion based on the scores collected and goes beyond them. It decides whether to believe what the sample data indicate about the scores that would be found in the population.
Inferential Statistics
Pertains to the entire collection of events.
population
Refers to the set of individuals taken from a population.
sample
It describes the characteristics of a population of scores.
parameter
It is the value that describes a sample.
statistics
It is the characteristics that have varying values. it is what researchers try to measure.
variable
A possible number or category that a score can have.
value
A person’s value on a variable.
score
Types of Variables
Nominal/Categorical
Numerical
2 Types of numerical or quantitative data
Discrete variable
Continuous variable
This variable has a specific value and cannot have values between specific values.
Discrete variable
This variable is an infinite number of possible values between any two values.
Continuous variable
2 Kinds of Variables
Independent variable
Dependent variable
This variable is the one that is manipulated and causes an event to happen.
Independent variable
This variable is the one being measured and is the one affected.
Dependent variable
This determines how you analyze a given data.
Levels of Measurement
4 Levels of Measurement
nominal
ordinal
interval
ratio
A level of measurement that is categorical and has no ordering.
Ex: marital status, gender, types of car owned
nominal
A level of measurement that is categorical and follows an order.
Ex: ranking, service quality rating, student letter grades
ordinal
A level of measurement that has intervals between variables but no true zero .
Ex: Temperature in Fahrenheit, standardized exam scores
interval
A level of measurement that has intervals between variables and possess an absolute zero.
Ex: age, height, weekly food spending
ratio
3 tools to summarize data
Frequency table
Histograms
Frequency distribution
This is a table that summarizes data by listing individuals with varying values for a certain variable.
Frequency table
A bar-like graph with the values in the horizontal (x) axis and the frequency on the vertical (y) axis.
Histogram
True or False. Bar graph is used instead of histogram only when data is nominal.
True
A distribution that displays the pattern of frequencies over various variables.
Frequency distribution
4 forms/types of Frequency distribution
Unimodal distribution
Bimodal distribution
Multimodal distribution
Rectangular distribution
It is a distribution that shows one value as the most frequent.
Unimodal distribution
It is a distribution with two approximately equal frequencies.
Bimodal distribution
It is a distribution with 2 or more higher frequencies, separated by lower frequencies.
Multimodal distribution
In this distribution all values have approximately the same frequencies.
Rectangular distribution
3 types/forms of Frequency distribution
Symmetrical distribution
Skewed to the right distribution
Skewed to the left distribution
This distribution’s one side is a mirror of the other side.
Symmetrical distribution
This distribution’s right tail is longer and frequency is higher on the left side.
Skewed to the right distribution (positively skewed)
This distribution’s left tail is longer and frequency is stacked on the right side.
Skewed to the left distribution (negatively skewed)
This effect is achieved when the distribution is skewed to the right where the scores are piled up at the low end.
floor effect
This effect is achieved when the distribution is skewed to the left where the scores are piled up at the high end.
ceiling effect
It is the Greek term for Kurtosis that means curve.
kyrtos
This refers to how much the shape of a distribution differs from a normal curve.
Kurtosis
normal, heavy-tailed, low-tailed
Methods of Data Collection
Interviews Questionnaires Experiments Direct Observations Use of existing records
Methods of Data Presentation
Textual method
Tabular method
Graphical method
It is presenting data through text.
Textual method
It is the presentation of data in a systematic manner.
Tabular method
This presents data in a pictorial form.
Graphical method
This chart presents historical data.
Line chart
It is a chart that compares amounts in a time series data.
Column chart
This chart presents distribution of categorical data.
Horizontal Bar chart
It is a chart divided into several sections wherein the biggest slice must be placed at 12 o’clock and there should only be less than 6 categories.
Pie chart
This presents magnitude through symbols and pictures.
Pictograph
