COG170 Chapter 9: Summaries Cogito
Fundamentals August 2018 Detailed
Questions With Solutions
What causes of concern would we have about a table component with the following threshold
settings?
Column Lower Bound Upper Bound Alert
Percent 34 67 Yellow
Percent 0 33 Green
Percent 68 Red
a. Percent thresholds should divide into perfectly equal parts (e.g. 33.33, 66.66)
b. The thresholds do not account for decimal percent values
c. Percent values are unavailable for threshold logic
d. Alerts should always be ordered from lowest to highest severity, or highest to lowest severity
b. The thresholds do not account for decimal percent values
Whichever summary format the report builder chooses, they will have to specify how the data is
grouped - what does that mean? Grouping - All summarization formats fundamentally
group data by common characteristics, and then perform summarization functions on all the data
which shares that characteristic.
, COG170 Chapter 9: Summaries Cogito
Fundamentals August 2018 Detailed
Questions With Solutions
What is a summarization function? Once data has been grouped, summarization functions
aggregate the data and define how it should be displayed for each group. Choosing the wrong
summarization function can obfuscate the data.
Define - Summarization Functions - Count Tells how many non null values there are!
Count - One of the most common summarization functions is count. Counting a column means
that for each group, your summary will show how many rows in the group have a value in that
column. Count does not care what the value is, only that it exists. This means the only rows not
counted are those containing a NULL in the counted column.
Define - Summarization Functions - Count Unique How many different values! Counting
unique values in a group is very different from performing a simple count. Counting unique
values will display the number of different values stored in a column for each group. NULL
values will still not be counted.
Define - Summarization Functions - Sum Adds together - Sum is only used for numeric
columns. It adds up the values in a column for each group. When adding up numbers, neither a 0
nor a NULL will affect the total sum.
Fundamentals August 2018 Detailed
Questions With Solutions
What causes of concern would we have about a table component with the following threshold
settings?
Column Lower Bound Upper Bound Alert
Percent 34 67 Yellow
Percent 0 33 Green
Percent 68 Red
a. Percent thresholds should divide into perfectly equal parts (e.g. 33.33, 66.66)
b. The thresholds do not account for decimal percent values
c. Percent values are unavailable for threshold logic
d. Alerts should always be ordered from lowest to highest severity, or highest to lowest severity
b. The thresholds do not account for decimal percent values
Whichever summary format the report builder chooses, they will have to specify how the data is
grouped - what does that mean? Grouping - All summarization formats fundamentally
group data by common characteristics, and then perform summarization functions on all the data
which shares that characteristic.
, COG170 Chapter 9: Summaries Cogito
Fundamentals August 2018 Detailed
Questions With Solutions
What is a summarization function? Once data has been grouped, summarization functions
aggregate the data and define how it should be displayed for each group. Choosing the wrong
summarization function can obfuscate the data.
Define - Summarization Functions - Count Tells how many non null values there are!
Count - One of the most common summarization functions is count. Counting a column means
that for each group, your summary will show how many rows in the group have a value in that
column. Count does not care what the value is, only that it exists. This means the only rows not
counted are those containing a NULL in the counted column.
Define - Summarization Functions - Count Unique How many different values! Counting
unique values in a group is very different from performing a simple count. Counting unique
values will display the number of different values stored in a column for each group. NULL
values will still not be counted.
Define - Summarization Functions - Sum Adds together - Sum is only used for numeric
columns. It adds up the values in a column for each group. When adding up numbers, neither a 0
nor a NULL will affect the total sum.
