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Data Acquisition and Analysis
Session-II
2
Content
Types of Data, Descriptive Statistics techniques as
applicable to different types of data, Types of graphs as
applicable to different types of data, Usage of Microsoft
Excel tool for descriptive statistics, Data Acquisition
(Temperature and humidity) using Sensors interfaced
with Arduino, Exporting acquired data to Microsoft Excel
and analysis using visual representation.
RIT, Rajaramnagar 3
Unit Learning Outcomes
• Apply the Descriptive Statistics techniques on
different types of data.
• Show the descriptive statistics using Microsoft
Excel Tool.
• Analyze the data acquired through
sensors/mobiles and represent it graphically
Data Acquisition System
• Data acquisition is the process of measuring physical quantities
such as voltage, current, temperature, pressure, or sound with
the help of electronic and mechanical devices. The process is
usually carried out by using an array of sensors connected with a
computer.
• A data acquisition system is a combination of hardware and
software components that enable a computer to receive and
interpret some physical form of signal.
Why is Data Acquisition necessary?
• The first requirement for any scientific claim to
be acceptable is to be backed by some
physical observations and measured data. This
is where data acquisition techniques come
into play.
What are the basic components of a Data
acquisition system
In short, a data acquisition system can be divided into three
parts:
• Sensors: Sometimes also called transducers, convert some
physical quantity, such as pressure, temperature etc. to a
corresponding voltage signal. Sensors are mainly of two
types, analog and digital sensors.
• Processing Unit: Receives the sensor input and is used for
signal conditioning and analog to digital conversion.
• Computer: Acts as a means to process, interpret, store and
display the data received from the processing unit to a user
readable format with the help of some suitable software.
Data
• Data is a collection of figures and facts, and is raw,
unprocessed, a
• Information isn’t just data that’s been neatly filed away, it has
to be ordered in a way that gives meaning and contextnd
unorganized.
Types of Data
1. Categorical data
2. Measurement data
Categorical Data
• The objects being studied are grouped into
categories based on some qualitative trait.
• The resulting data are merely labels or
categories.
Examples
• Hair color
– blonde, brown, red, black, etc.
• Opinion of students about riots
– ticked off, neutral, happy
Categorical data
• Nominal Data
– A type of categorical data in which objects fall into
unordered categories.
– Ex. Hair color – blonde, brown, red, black, etc
• Ordinal Data
– A type of categorical data in which order is
important
– Ex. Class– fresh, sophomore, junior, senior, super
senior
Categorical data
• Binary Data
– A type of categorical data in which there are only
two categories.
– Binary data can either be nominal or ordinal.
– Ex. Attendance– present, absent
Class– lower classman, upper classman
Measurement Data
• The objects being studied are “measured” based
on some quantitative trait.
• The resulting data are set of numbers.
• Example
– Cholesterol level
– Height
– Age
– Number of students late for class
– Time to complete a homework assignment
Measurement Data
Discrete Measurement Data
Only certain values are possible (there are gaps between the
possible values).
Continuous Measurement Data
Theoretically, any value within an interval is possible with a fine
enough measuring device.
Discrete and Continuous data
Examples
• Discrete Data
– Number of students late for class
– Number of crimes reported to SC police
– Number of times the word number is used
Generally, discrete data are counts.
• Continuous Measurement Data
– Cholesterol level
– Height
– Age
– Time to complete a homework assignment
Generally, continuous data come from measurements.
Who cares?
The type(s) of data collected
in a study determine the type
of statistical analysis used.
Statistics
• Statistics is concerned with the scientific
method by which information is collected,
organised, analysed and interpreted for the
purpose of description and decision making.
Types of Statistics/Analyses
Descriptive Statistics
– Frequencies
– Basic measurements
Inferential Statistics
– Hypothesis Testing
– Correlation
– Confidence Intervals
– Significance Testing
– Prediction
Describing a phenomena
How many? How much?
BP, HR, BMI, IQ, etc.
Inferences about a phenomena
Proving or disproving theories
Associations between phenomena
If sample relates to the larger
population
E.g., Diet and health
Sample vs. Population
Population Sample
Population - A population is the group from which data are to be collected.
Sample - A sample is a subset of a population.
Variable
• A variable is a feature characteristic of any
member of a population differing in quality or
quantity from one member to another.
Variable
• Quantitative variable - A variable differing in quantity
is called quantitative variable, for example, the
weight of a person, number of people in a car.
• Qualitative variable - A variable differing in quality is
called a qualitative variable or attribute, for example,
color, the degree of damage of a car in an accident.
• Discrete variable - A discrete variable is one which no
value may be assumed between two given values, for
example, number of children in a family.
• Continuous variable - A continuous variable is one
which any value may be assumed between two given
values, for example, the time for 100-meter
Primary and Secondary Data
• When data is used for the purpose for which it
was originally collected it is known as primary
data;
• When it is used for any other purpose
subsequently, it is termed secondary data.
Micro Activity
Read it
“A picture is worth a thousand words”
Graphical Descriptions of Data
• A graph is a method of presenting statistical
data in visual form.
• The main purpose of any chart is to give a
quick, easy-to-read-and-interpret pictorial
representation of data which is more difficult
to obtain from a table or a complete listing of
the data.
Types of graphs
• Pie chart
• Simple bar chart
• Multiple bar chart
• Component bar chart
• Other type of graphs
Jan
Feb
M
ar
Apr
M
ay
Jun Jul
Aug
Sep
Oct
Nov
Dec
Average
Users / M
onth
Average
users / Day
0
500
1000
1500
2000
2500
Chart Title
Staff Students
Staff
01/01/2017 02/01/2017 03/01/2017 04/01/2017 05/01/2017
06/01/2017 07/01/2017 08/01/2017 09/01/2017 10/01/2017
11/01/2017 12/01/2017
Activity
• Create chart for the given data.
Activity
Team Activity Duration : 60 minutes
Rainfall Analysis for a given area
Note: Rainfall data is given for an area for a particular year
Students have to find out the following
Average rainfall
To draw hydrograph
To draw flow duration curve
Average Function of MS Excel
Graph Function of MS Excel
Mode Min, Max Function of Excel
09/26/2025 31
Frequency Histograms
Relative Frequency Histograms
• construct a diagram by drawing for each group,
or class, a vertical bar whose length is the
relative frequency of that group.
Histogram
Central Tendency
• Arithmetic Mean
• The arithmetic population mean, μ, or simply
called mean, is obtained by adding together all
of the measurements and dividing by the total
number of measurements taken.
Mathematically it is given as
• i
Central Tendency
• Median
– Median is defined as the middle item of all given
observations arranged in order.
– the median is obtained by taking the average of
the middle
• Mode
– Mode is the value which occurs most frequently.
The mode may not exist, and even if it does, it
may not be unique
Dispersion and Skewness
• Range
– Range is the difference between two extreme values.
• Deciles, Percentile, and Fractile
– Decile divides the distribution into ten equal parts while
percentile divides the distribution into one hundred equal parts.
• Quartiles
– Quartiles are the most commonly used values of position which
divides distribution into four equal parts
• Mean absolute deviation
– Mean absolute deviation is the mean of the absolute values of
all deviations from the mean.
• Variance and Standard Deviation
Thank You