Mar 12:22 PM
What is DATA?
Data can be organized into tables and graphs.
DATA is the information or facts collected about a topic of study.
Mar 12:20 PM
What is POPULATION?
In Data Management, POPULATION refers to the group of
people or objects which are the subject of a study.
When conducting a study, it is important to define the
population of that study.
WHY?
Defining the population helps to focus the study further and to clarify how
that study should be conducted.
EXAMPLE: A study is to be conducted about whether or not St. Francis Xavier High
School should adopt uniforms. Who is the population of this study?
Mar 12:20 PM
What is a CENSUS?
When the entire POPULATION is studied or surveyed about a
topic, a CENSUS has been conducted.
THE CANADIAN CENSUS
• Statistics Canada conducts a Canadian Census every 5 years.
• Participation in the Canadian Census is mandatory and failure to participate can lead to legal punishment.
• Information collected through the Canadian Census informs the government about the country's demographics (ex. population and average income), and is used to plan public services (ex. health care, education, and transportation) or government structure (ex. number of MPs per Province or Territory).
Mar 12:20 PM
Population vs. Sample
It is often unrealistic to collect data from an entire population (ie. conduct a
CENSUS).
WHY?
A CENSUS can be too expensive, time consuming or impossible (population may be in
flux or unreachable).
Instead, a SAMPLE of the POPULATION is selected.
A SAMPLE is a portion of the POPULATION
chosen to represent the entire POPULATION.
• If the SAMPLE is chosen well, it will create an accurate picture of the population; in other words, it will be representative of the population.
• A proper sample allows INFERENCES to be made about the population. That is, conclusions are drawn from the study of the SAMPLE and these are assumed to be true about the entire population.
A Few Notes About Samples:
POPULATION
Mar 12:20 PM
Population vs. Sample
EXAMPLE:
Mr. Curry asks the Data Management class to conduct a study to
determine what foods should be served in the cafeteria.
Who is the population of this study?
The population would be the staff and students of St. FX as well as the Cafeteria staff.
What would a CENSUS for the is study involve?
A CENSUS would involve surveying all the students and staff at St. FX (including the
cafeteria staff) about their food preferences for purchase at the cafeteria.
What would a SAMPLE be for this study?
A SAMPLE for this study would be a smaller group of students and staff from St. FX
chosen to represent the entire population.
Apr 11:43 PM
UNIT 03: ORGANIZATION OF DATA
Lesson 1: DATA: Role, Variability, Characteristics and Type
A) Role of Data
1.
2.
3.
B) Variability
1.
2.
3.
Mar 12:18 PM
SCALES OF MEASUREMENT DATA:
NOMINAL DATA
• have no order and thus only gives names or labels to various categories • data has just a name • sex, species, marital status, individuals LESS ORDER MORE ORDER
INTERVAL DATA
• have meaningful intervals between measurements, but there is no true starting point (zero). • has order and equal interval between levels • Celsius temperature, tide height, longitudeORDINAL DATA
Apr 11:52 PM
D)
Types of Data
Primary vs. Secondary
Experimental vs. Observational
Microdata vs. Aggregate data
Mar 12:22 PM
TYPES OF DATA SETS
present the total number of
occurrences within a category,
not individual data.
•
For example, Statistic Canada
gives a summary of data collected
from each province.
Microdata sets
are files that show the full range of
responses individuals complete in
a certain category.
•
For example, a table that lists out
each individual's answers from a
survey or questionnaire.
Take a look at the data sets shown in the tables below. Can you describe how they are different?
Apr 11:54 PM