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CHAPTER 15: Data Preparation and Analysis of Data - Coggle Diagram
CHAPTER 15: Data Preparation and Analysis of Data
Introduction
Data preparation
A process of inspecting, cleaning, transforming and modeling data with goal of highlighting useful information, suggesting conclusion, and supporting decision making.
has multiple facets and approaches, encompassing diverse techniques under a variety of names.
Data Preparation
Logging The Data
Source
mail surveys returns
coded interview data
pre-test or post test data
observational data
procedure for logging in the information and keep track of incoming data
set up database
Checking the Data for Accuracy
Question to asked as part of initial data screening
Are the responses legible/readable?
Are all important questions answered?
Are responses complete?
Is all relevant contextual included?
data
time
place
researcher
Developing a database
to store data for study for analysis
option for storing data on computer
database program
statistical program
Codebook
variable name
variable description
variable format
number
data
text
instrument/method of collection
data collected
respondent/group
variable location
in database
notes
Entering the Data into the Computer
alternatives
type the data directly
easiest way
double entry
high level of accuracy
reduce entry error
Data Transformations
transform raw data into variables
missing values
item reversals
scale totals
categories
The Process of Data Analysis
Data Cleaning
can be done during the stages of data entry
no subjective decision are made
The guiding principle
during subsequent manipulations of data
information should always be cumulatively retrievable
Initial Data Analysis
Quality of Data
Alternative to assess data quality
frequency count
description statistics
mean
standard deviation
median
normality
skewness
kurtosis
frequency histogram
normal probability plots
associations
scatter plots
correlations
Quality of Measurement
possible transformation of variables
square root transformation
log transformation
inverse transformation
make categorial
ordinal
dichotomous
possible data distortions should be checked
dropout
item nonresponse
treatment
Characteristics of Sample Data
can be assesed by looking at
basic statistics of important value
scatter plots
correlations
cross-tabulations
analyses that can be used during the initial data analysis phase
univariate statistics
bivariate associations
graphical technique
Main Data Analysis
aim to answer the research questions are performed as well as other relevant analysis needed to write the first draft of the report