- Operationalization
- Conceptualizing is where you define your research problem and explain the constructs and
theories that are relevant.
- Conceptual definitions explain your constructs by telling what they are and showing how they
relate to other constructs.
- This explanation and all of the constructs it refers to are abstract.
- To work with your constructs, you must establish a connection between them and the concrete
reality in which you live.
- This process is called operationalization.
- Operational definitions describe the variables you will use as indicators and the procedures you
will use to observe or measure them.
- The connection between conceptual and operational definitions plays
a crucial role in research.
- It determines the connection between your abstract constructs and the concrete reality in which
you live.
- This means that a valid connection is a necessary component of all valid research.
- Although a valid connection by itself isn't enough to guarantee that the research will be valid, an
invalid connection guarantees that the research will be a useless and misleading waste of time.
- The part of the conceptual definitions where you specify the essential
qualities is especially relevant here ...
- It gives some very good clues about how you can measure the concept in a straightforward way:
- Look for the presence or absence of the essential qualities.
- Choose variables that are indicators of the essential qualities.
- To measure a construct, you need an operational definition that specifies:
- first, the variable you will use as an indicator of the construct, and
- second, the procedures you will use to measure the variable.
- The operational definition thus associates a variable with a construct.
- Creating this association--choosing a variable to be an indicator--requires you to use both your:
- logical skills of deduction
- (if you want to measure intelligence, the variables you choose as indicators of intelligence must
somehow actually "tap into" intelligence)
- and your ability to use creativity and insight to conceive of an appropriate indicator
- (there is no straightforward way to produce indicators for constructs; there are no standard
formulas or recipes)
- Once you have selected indicators for your constructs, you can begin to
take measurements.
- There are four kinds of measurements you can take:
- you can sort things into categories
- you can arrange them in increasing or decreasing order
- you can count them
- you can measure amounts and distances
- It's important to know which kind you are doing because
- they use different procedures,
- they produce different results, and
- they make different things possible or impossible to do.
- Sorting things into Categories -- Examples:
- What is your occupation?
- What is your first language?
- What is your marital status?
- When you are sorting things into categories, the variable tells which category whatever you are
sorting has been placed into.
- With this kind of measurement, the only thing you can say about an individual is which category it
belongs to.
- More on Categories ...
- You will want to name your categories.
- Here are a few examples of category names:
- John/Martha
- Canucks/Rangers/Bruins
- Door #1/Door#2/Door#3
- Each category must have a unique name.
- The names don't have any particular meaning; they are nothing more than labels.
- If you use numbers in the names, the numbers won't have any of the properties that ordinary
numbers have:
- you can't add or subtract them and the ordering of the numbers will have no meaning.
- Sorting things into increasing or decreasing order
- When you sort things into increasing or decreasing order, you compare pairs of things like you do
when you are sorting them into categories.
- However, instead of asking if they are the same or different, you ask if the first one is smaller than,
the same as, or larger than the second one.
- With this kind of sorting, you end up with a set of ordered categories where the members of any
one category are either larger or smaller than the members of other categories.
- Although you can say that one thing is larger or smaller than another, you can't tell how much
larger or smaller it is.
- More on sorting into increasing or decreasing order
- With this kind of sorting, the placement of a thing into a particular ordinal position, say "third
largest," tells where that thing is in relation to all the other ordinal positions.
- The third largest position is smaller than the largest and second largest, but it is larger than the
fourth and fifth largest positions.
- You see things that behave (in some ways) like numbers:
- "1st," "2nd," and "3rd" specify the ordinal position of the categories in a way that "Joe," "Sam,"
and "Linda" don't.
- But you can't do any arithmetic on them.
- You can't add 1st to 3rd.
- Measuring amounts and distances
- Measuring amounts and distances is similar to counting, except you are not restricted to whole
numbers.
- You may find that 19.348 percent of an issue of The Globe and Mail is occupied by advertising.
- There may be 9.74 minutes between one televised murder and the next.
- You use measures of distance for locations of things in physical or conceptual space, and measures
of duration for events located in time.
- Measuring amounts, distances, and durations, like counting things, uses numbers which you can
add, subtract, multiply, or divide.
- Once again, the value "0" means "none."
- Scaling
- Scaling and mapping are ways of matching numbers or numerals to objects or events or qualities.
- Scaling is the process of using numbers to represent phenomena in the world.
- It's called scaling because it involves use of a scale to measure something.
- Some examples are:
- bathroom scales,
- tape measures,
- "one-to- ten" ratings,
- batting averages,
- GPA
- Numerals
- Numerals are symbols used as labels to indicate which category something belongs to.
- They are only symbols, like letters, and they have no mathematical meaning.
- This is the kind of mapping you do when you sort things into categories.
- Wayne Gretzky's "99" is an example.
- Ordinals
- Ordinals are numerals that can be used in arithmetical comparisons,
- such as "greater than," "less than," or "equal to"
- ... but not in arithmetical operations, such as addition and multiplication.
- Ordinals take values like "1st," "2nd," and "3rd."
- Numbers
- Numbers, like ordinals, are numerals that can be used in arithmetical comparisons, such as "greater
than,"
- but they can also be used in arithmetical operations, such as addition, subtraction, multiplication,
and division.
- They have mathematical meaning--how many, how much, etc.
- Variables may be discrete or continuous.
- A variable that can take any value between the lowest and highest points is continuous;
- there are an infinite (or very large) number of possible values within the range.
- A variable that can take only a small number of specific values is discrete.
- Sand, water, income, and freedom are continuous.
- Family size, number of cars owned, and gender are usually considered to be discrete
- Discrete or Continuous
- Things that are counted or categorized generally result in discrete results:
- you speak of the number of people, the number of movies, etc.
- Things that are measured in terms of quantity, distance, or magnitude generally result in
continuous results:
- you speak of the length of time that has passed, the amount of money you have, the height of a
building, the brightness of a lamp
- Levels of Scaling
- Most textbooks distinguish four levels of scaling:
- nominal,
- ordinal,
- interval,
- ratio.
- As you move from nominal to ratio, the numbers in the data contain more information and more
kinds of information about whatever it is the numbers represent.
- Nominal Scaling
- With nominal scaling, all you are doing is sorting the cases into categories.
- Each category is associated with a numeral, which is the name of the category.
- The numerals don't mean anything in the sense that they don't imply how much or how many or
how far or anything like that; they are just labels for the categories.
- No arithmetic operations can be performed on the numerals associated with categories, because
they aren't numbers--they are the names of the categories.
- Here's an example of Nominal scaling
- Do you like chocolate?
- ___ 1. Yes ___ 2. No
- When you see a "1" for someone, it means that that person does like chocolate.
- When you see a "2" for someone, it means that that person doesn't like chocolate.
- Ordinal Scaing
- With ordinal scaling you order the cases into a set of increasing (or decreasing) categories.
- One comes first, another comes second, etc.
- You don't know how far apart one category is from the next, but you can tell how many categories
come before or after the one you are looking at.
- Here the numerals associated with categories behave a bit like numbers -- they tell the ordinal
positions of the categories -- but they still aren't numbers; they are ordinals.
- No arithmetic operations can be performed on ordinals -- no addition, subtraction, etc.
- Here's an example of Ordinal scaling
- Do you like chocolate?
- __ 1. I don't like it.
- __ 2. A little bit.
- __ 3. Quite a bit.
- __ 4. A lot.
- __ 5. I've killed for chocolate.
- You can see that a person who answers 4 ("A lot") likes it more than someone who answers 3
("Quite a bit") ...
- but you can't tell how much more.
- Interval Scaling
- Interval scaling puts each case on a scale that can be likened to a ruler.
- Cases aren't sorted into categories; they can be anywhere on the scale (e.g. "3.14159").
- Here you can look at the distance between points and you measure the distance in some kind of
units.
- To do this, you subtract the number associated with one case from the number associated with a
second case.
- Examples: Fahrenheit and Centegrade temperature scales
- Ratio Scaling
- Ratio scaling is the most powerful.
- It has everything interval scaling has,
- and it also has a fixed absolute zero point.
- With Ratio scaling, "0.0" means "none"
- You tell both the distance between values
- The difference between $10.45 and $11.55 is $1.10
- and the relative sizes or magnitudes of values
- Example: A person who is 8 feet tall is twice as tall as a person who is 4 feet tall.
- An example of Ratio scaling
- On a zero-to-ten scale, where "0" means "not at all" and "10" means "more than anything else that I
could eat" and "5" means halfway between those two,
- how much do you like chocolate?
- Your answer can be any number from "0" to "10".
- You can talk about relative amounts of liking:
- You know that a person who says "10" likes it twice as much as a person why says "5".
- You can talk about differences in amounts of liking:
- A person who says "6" likes it 2 steps more than a person who says "4" who likes it 2 steps more
than a person why says "2".
- Comparing two Nominal values
- The only thing you can say about the categories associated with two cases is:
- they are the same
- they are different
- one likes it and one doesn't
- Because you can't do arithmetic on nominal data, you can't say how big the difference might be.
- Comparing two Ordinal values
- With Ordinal data, you can tell if one case comes before or after another case
- someone who likes chocolate "a lot" likes it more than someone who likes it "quite a bit"
- but not how far before or after
- what is the difference between "a lot" and "quite a bit"?
- because you can't do arithmetic on ordinals.
- Comparing two Interval values
- You can tell both order and distance between points,
- but you can't talk about how big one value is as a fraction of another.
- Subtracting one value from another is okay;
- multiplying and dividing are not permitted.
- Example: It is 8 degrees today; it was 4 yesterday.
- You can't say that it is twice as warm today,
- but you can say it is 4 degrees warmer today.
- Comparing two Ratio values
- With Ratio data, you can tell order,
- this one is bigger than that
- distance,
- the difference between the two is 4.923
- and relative size (as a ratio)
- this one is twice as large as that one
- Adding, subtracting, multiplying and dividing of values is okay.