BIOE: INTRODUCTION TO BIOSTATISTICS Flashcards
• field of study concerned with
(1) the collection, organization, and analysis of data
(2) the drawing of inferences about a body of data when only a part of the data is
observed
Statistics
• tools of statistics when data analyzed are derived from the biological sciences and
medicine
Biostatistics
• science of summarizing data so that non-statistician can understand it
• can be used as a tool in decision-making
Biostatistics
• raw material of statistics
Data
Data sources:
• records of day-to-day transactions of its activities
• ex. hospital records & hospital accounting records
Routinely kept records
data sources:
• ex. administrator of a clinic wishes to obtain information regarding the mode of
transportation used by patients to visit the clinic
Surveys
Data sources:
• ex. nurse may wish to know which of several strategies is best for maximizing
patient compliance
Experiments
Data sources:
data needed to answer a question may already exist in the form of published
reports, commercially available data banks, or the research literature
External sources
Data types:
• firsthand data gathered by the researcher
Primary
Data types:
• data collected by someone else
Secondary
• characteristic that takes on different values in different persons, places, or things
Variable
• characteristics are not capable of being measured
Qualitative variables
• value of a characteristic that remains the same from person to person, from time
to time or from place to place
Constant variable
characteristics takes on different values
Random variable
TYPES OF QUANTITATIVE VARIABLE
• can assume a finite or ____________
number of values
• characterized by gaps or interruptions in the values that it can assume
Discrete
TYPES OF QUANTITATIVE VARIABLE
• can assume an____________ or other possible values
• does not possess the gaps or interruptions
Continuous
• largest collection of entities for which we have an interest at a particular time
• value is denoted by ____
Population
• part of a population
• value is denoted by ____
Sample
• measure of a characteristic of a population
Parameter
SCALE OF MEASUREMENT OF VARIABLES
• simply used as names or identifiers of a category
• always ____________
• does not represent any amount or quantity
Nominal
SCALE OF MEASUREMENT OF VARIABLES
• represents an ____________ series of relationships
• may be qualitative or quantitative
Ordinal
SCALE OF MEASUREMENT OF VARIABLES
• does not have a true-zero value or starting point
Interval
SCALE OF MEASUREMENT OF VARIABLES
• modified interval level which includes zero as a starting point
Ratio
BRANCH OF STATISTICS
• methods of summarizing and presenting data
• computation of measures of central tendency and variability
• tabulation and graphical presentation
• facilitate understanding, analysis, and interpretation of data
Descriptive Statistics
BRANCH OF STATISTICS
• methods of arriving at conclusions and generalizations about a target
population based on information from a sample
• estimation of parameters and hypotheses testing
Inferential Statistics
• systematic procedure to ensure that the information/data gathered are complete, consistent and suitable for analysis.
DATA PROCESSING
METHODS OF DATA PROCESSING
• without using any machine or tool to get the required results
Manual
METHODS OF DATA PROCESSING
• uses typewriters or mechanical printers
Mechanical
METHODS OF DATA PROCESSING
• uses computers softwares such as MS Excel, SPSS to collect and summarize
data
Electronic
• conversion of verbal/written information into numbers which can be more easily
encoded, counted and tabulated.
DATA CODING
DATA CODING
actual value or information given by the respondent
Field Code
DATA CODING
recorded as range of values rather than actual values
Bracket Code
DATA CODING
codes are assigned to a list of categories of a given variable
Factual Code
DATA CODING
applicable for questions with multiple responses
Pattern Code
• A document which contains a record of all codes assigned to the responses to
all questions in the data collection forms
CODING MANUAL
• Entering the data/responses in a spreadsheet
• MS Excel
• MS Access
• Epi Info
DATA ENCODING
• process of examining and adjusting the data collected in questionnaires to
detect errors and omissions, legibility, consistency and readying them for coding
and storage
• detects errors and omissions, corrects them when possible and certifies that
minimum data quality standards are achieved
• performed during data collection, encoding, before data analysis
DATA EDITING
Types of editing
• done by enumerator or a filed supervisor on the same data as the interview
• reviewing the accomplished data collection forms
• decoding of abbreviations or special symbols
• making callbacks/messages for verification/clarification of incomplete answers
Field Editing
• also known as in house editing
• done by the researcher or a central office staff after getting all the questionnaires/
forms from the enumerator or respondents
• checking of inconsistencies and incorrect entries after receiving the questionnaire
from the field
• more rigorous than filed editing
• checking of encoded data
Central Editing
