ICT 110 Detailed Final Exam 2025
Data - Correct Ans-The symbols that represent people, events, things, and ideas.
Consists of the raw, unprocessed facts, including text, numbers, images, and sounds.
Everything has its features (color , size, name...)
Abstract the objects to data which are easy to express.
Information - Correct Ans-Data becomes information when it is presented in a format
that people can understand and use.
Knowledge - Correct Ans-is created when the information is learned, applied and
understood.
Data Science - Correct Ans-is the extraction of knowledge from data.
-Human have done this thousands of years ago
-But we are facing an unprecedented scale
Big Data - Correct Ans-Huge amount of data
- volume
- variety
- velocity
- veracity
-2.5 quintillion bytes of data every day. -That is, 90% of all data today has been created
in the last two years alone. (IBM)
-Walmart has 1 million+ transactions every hour, which are over 2.5 petabytes of
information.
-Facebook currently holds more than 45 billion photos in its user data base.
-Human Genome Project has 3 billion pairs
4Vs of Big Data - Correct Ans-- volume: scale of data
- variety: different forms of data
- velocity: analysis of streaming data
- veracity: uncertainty of data
Variable - Correct Ans-Bind a name with a value to simplify its usage
- value can be changed.
- names consist of letters, numbers, and underscores
- nouns
Function - Correct Ans-- Represent an action
- verbs
- Functions can take variables which are also called as parameters
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- x <- 5
- eat( x )
- max(x), mean(x), plot(x), ...
- q(), help(), help(max)
Vector - Correct Ans-A sequence of numeric or character values
- Similar names: list, array
- Use function c() to concatenate many values into a vector
- c(2, 4, 6)
- numeric_vector <- c(1,10,49)
- character_vector <- c("we","like","R")
Functions can be applied on vectors
- sum(numeric_vector)
- max(numeric_vector)
- length(character_vector)
Element Selection in Vectors - Correct Ans-Select only one or some of the elements
- Vector elements are indexed from 1 to its length
- Select elements by using their indices in square brackets [ ]
- numbers <- c(5,10,15,20,25)
Conditional selection with logical expressions
- numbers[numbers == 15]
- numbers[numbers > 15]
Update the selected elements
- numbers[3] <- 0
Data frame - Correct Ans--Most data sets are in the form of tables
-A data frame is a table with two dimensions
- Column: a feature / attribute
- Header: the top line if it contains the column names.
- Row: a data record or item
- (optional) row name
- the actual data
- Cell: one data item in a row
Element Selection in Frames - Correct Ans-To select data cells in a table, we need two
coordinates: [row, column]
- Data frames support conditional selection, again with two coordinates: [row, column]
Data types - Correct Ans-- numeric
- Real numbers, eg. 1.0, 3.14, ...
- integer
- Integer numbers, eg. -2, -1, 0, 1, 2,..
- character
- Strings, eg. "text", "1", "a test", ...
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- factor:
- Categorical data, simple classifications. Eg. gender includes "M" and "F"
Sampling - Correct Ans-Get a representative subset of data points to identify patterns
and trends in the larger data set
- Storage limit
- Computation limit
- Cost limit
- Time limit
Simple Random Sampling - Correct Ans-There is an equal probability of selecting any
particular item
Sampling without replacement - Correct Ans-Once selected, the item is removed from
the population
Sampling with replacement - Correct Ans-Objects are not removed from the population
after they are selected
- The same object can be picked up more than once
Stratified sampling - Correct Ans-- Split the data into several partitions, or strata
- Draw random samples from each stratum
Analog data - Correct Ans-A continuous representation, analogous to the actual
information it represents.
- mercury thermometer
- Most signals around us are analog
- Sound, vision, ...
Digital data - Correct Ans-A discrete representation, breaking the information up into
separate elements.
- digital clock
Analog data vs. Digital data - Correct Ans-- Computers work with binary representation
- Computers are inherently binary
- Less expensive and far more reliable if they only need to represent one of two
possible values
- Conversion between analog and digital is vital for computers
- Digitize information by breaking it into pieces and representing those pieces
separately.
File - Correct Ans-A named sequence of bytes
File system - Correct Ans-- A collection of files organized within a hierarchical
namespace
- Provide file management
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