CORRECT (VERIFIED)
Simple indexing - Answers -✔✔ Common analytic measure to improve performance.
Compares current data with data during a base period.
(Price / Price during "Base Period") x 100
i.e. Big Mac was 1.60 in 1968 which is base period. what is index for 2014 if price was
4.80 then?
(4..60) * 100 = 300 (means price is 3x greater than base period)
Descriptive Analytics - Answers -✔✔ using current and past data for strictly descriptive
purposes.
i.e. car price data shows a 2% increase over the prior year
a manager wants to know why sales spiked during the prior quarter
Predictive / Inferential Analytics - Answers -✔✔ using current and past data to
predict/estimate future.
i.e. based on the past 10 years of data for car prices, we predict an increase of 1.5%
over the upcoming year.
Used to identify price fluctuations of supplies, materials, products, etc.
Weighted Index - Answers -✔✔ assign a weight to allow for significant differences in the
index.
Reasons for including analytics in decision-making - Answers -✔✔ decrease cost of
data storage
increase processing power
Prescriptive Analytics - Answers -✔✔ using past data to PREDICT or ESTIMATE future
in order to optimize operations
includes experimental design and optimization to aid in DECISION-MAKING.
MANAGERIAL DECISIONS.
,i.e. based on past data, sales prices for electric cars could increase by 5% if we
increased charging stations by 7%
Big data - Answers -✔✔ Data so big that it's difficult to process using traditional
methods.
Stored in a Data Warehouse.
Mined to identify patterns and trends
Primary purpose is to encourage buying behavior.
Enables products to be more tailored to customer base.
Improves decision-making.
Supports development of next generation products/services.
watch for keywords in test options. i.e. company TOTAL sales (just one number) vs all
sales invoices
Structured / Quantitative Data - Answers -✔✔ Data follows pre-defined formats.
i.e. multiple choice answers, addresses, names, stock tickers
Unstructured / Qualitative Data - Answers -✔✔ Data doesn't follow pre-defined formats.
Usually gets structured by a "theme analysis"
i.e. blocks of freeform text, audio, video
Continuous Data - Answers -✔✔ Data that can take any value (within a set range)
i.e. 3.14159, -189,115.2
a thermometer reads 66.5 degrees
Interval Data (data measuring levels) - Answers -✔✔ data is ordered at equal intervals
apart and "0" doesn't mean absence of data, just another data point
a type of continuous data
i.e. date, time, degrees
Ratio Data (data measuring levels) - Answers -✔✔ 0 actually means nothing, not just a
data point
a type of continuous data
,i.e. money, height weight
Discrete Data - Answers -✔✔ Data that can only take on whole values and has clear
boundaries
i.e. 4, 7, 8 in a preset range of 1-100
Ordinal data (data measuring levels) - Answers -✔✔ data is ordered based on quality
a type of discrete data
i.e. in blackbelt data, level "3" is higher quality than "1"
gold, silver, and bronze medals
Nominal / Categorical Data (data measuring levels) - Answers -✔✔ data is assigned a
category/label for identification and grouping purposes
a type of discrete data
i.e. males are assigned "0" and females "1"
potential quality errors: categories can be misspelled
Attribute Data - Answers -✔✔ Data that shows whether a result meets a requirement or
not (yes/no, pass/fail).
Davenport-Kim Three-Stage Model - Answers -✔✔ 1. Frame the problem - recognize
problem and review previous findings.
2. Solve the problem - modeling, collection, analysis
3. Communicate results - tailor to audience, use visuals, show results.
Reliability of Data - Answers -✔✔ data that is consistent (but not necessarily accurate)
i.e. a thermometer reads 20, 21, 21, 20, 20, 19, 19, 21, 20, 19
a test given to a student consistently shows similar scores
Validity of Data - Answers -✔✔ data that is accurate
requires sample selection to be adequate size and random.
, i.e. a thermometer consistently reads from 20-25 F but the water isn't even frozen (not
valid)
Data Error Types - Answers -✔✔ Omission - data being left out, missed, forgotten.
sorting in spreadsheet can help to identify
Out of Range - data that doesn't fit the expected, viable range. sorting in spreadsheet
can help to identify outliers.
Entry/input errors - typos, miscommunications, illegible handwriting
Systematic Error - Answers -✔✔ error will cause other errors until fixed
i.e. a tire pressure sensor breaks and stops functioning, resulting in omission errors until
fixed
a scale is calibrated prior to being used in order to reduce systemic error
Random Error / Unpredictable Error - Answers -✔✔ error that does not consistently
repeat due to system flaw and therefore doesn't need fix/adjustment. aka its "self fixing".
minimize effects by increasing sample size
i.e. a tire pressure sensor records an outlier / out-of-range caused by going over a
speed bump at high speed
True Score Theory - Answers -✔✔ Observed Score (raw data score) = true score +
random error score + systematic error
in absence of systematic error, it's just true score + random error
Measurement Bias - Answers -✔✔ data doesn't represent the study group because of:
1. sample isn't random enough
2. sample isn't big enough
3. sample wasn't inclusive enough, or was too inclusive, to represent study group
i.e. a survey on favorite foods was sent to all renters in a city (didn't include
homeowners so not a "Truly Representative Sample")
Conscious Bias - Answers -✔✔ the subject is biased towards a certain result because
he believes it will benefit him in some way
Information Bias - Answers -✔✔ response bias - people give different answers when the
response isn't anonymous and confidential