Appendix B: Definitions

Demographic variables
Readiness to learn measures
Home environment variables

Demographic variables

Several child and family characteristics were included as predictor variables in the analyses. They included:

Sex of child
Female or male

Household income of child’s home (see below for definition)

• Below LICO
• LICO to less than 2 times LICO
• 2 times LICO to less than 3 times LICO
• 3 times LICO or above

Education level of reporting parent
High school completion or less, or more than high school

Family structure
One-parent family or two-parent family

Country of birth of reporting parent
Not Canada or Canada

Kindergarten attendance of child
Not attending kindergarten or attending kindergarten

Community size
1. Rural
2. Population less than 30,000
3. Population 30,000 to less than 100,000
4. Population 100,000 to less than 500,000
5. Population 500,000 and over

Province of residence
Ten provinces

Household income status and low income cut-offs (LICO). Income status was measured using the income ratio variable in the data set, which is the ratio of household income to the LICO as reported by Statistics Canada for the size and location of the child’s household. The following information on the income ratio variable was taken from the Microdata User Guide of the NLSCY for cycle 1 (Statistics Canada n.d.a).

NLSCY children can be classified as living in households of various income levels. An income ratio has been derived and assigned to each child record and can be used for analytical purposes to further understand the economic situation of the child. The following is a description of how this ratio was calculated. Every year Statistics Canada establishes what are known as the low-income cut-offs, which are derived by considering expenditure to income patterns observed in the most recent Family Expenditure Survey. These thresholds or values are calculated for different urban-size and family-size categories and are updated annually using the Consumer Price Index. The cut-offs that were derived for 1994 were used to calculate the NLSCY income ratio. The ratio was simply calculated to be the household income divided by the cut-off value (p.63-64).

Similar procedures were used to calculate the NLSCY income ratio for 2002. Readers who require additional information on data quality issues related to the income ratio are referred to the Microdata User Guide for the NLSCY for cycle 1 or cycle 5 (Statistics Canada n.d.a, n.d.b).

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Readiness to learn measures

Receptive vocabulary score. The measure of receptive vocabulary was the standard score on the Peabody Picture Vocabulary Test – Revised (PPVT-R). More information about the PPVT-R in the NLSCY may be found in the Microdata User Guide for the NLSCY for cycle 5, page 169-171 (Statistics Canada n.d.b).

Communication skill score. The communication skill score included responses to a set of six individual items. The Cronbach’s alpha measure of internal reliability for this score was 0.63. Parents were asked:

1. How often does (CHILD): clearly convey HIS/HER needs?
2. When HE/SHE is paying attention, how often is (CHILD) able to carry out a simple instruction after hearing it only once?
3. If  HE/SHE does not understand what someone has said, how often will (CHILD) ask for it to be repeated or explained?
4. How often does (CHILD) follow what is being talked about in a conversation,and stay on the same topic?
5. How often can (CHILD) be relied on to pass simple messages from one person to another without getting the message mixed up?
6. How often does (CHILD) clearly explain about things HE/SHE has seen or done so that you get a very good idea what happened?

Response options were:  never, sometimes, and often. Responses were scored 0 for never, 1 for sometimes, and 2 for often. Possible scores ranged from 0 (low communication skill) to 12 (high communication skill).

Number knowledge score. The measure of number knowledge was the age-standardized score on the 22-question (30-item) Number Knowledge Assessment instrument. More information about the Number Knowledge Assessment instrument in the NLSCY may be found in the Microdata User Guide for the NLSCY for cycle 5, page 172-173 (Statistics Canada n.d.b).

Copying and symbol use score. The measure of copying and symbol use was the standard score on Who Am I?, an instrument that evaluates the developmental level of young children (De Lemos 2002). More information about the copying and symbol use instrument in the NLSCY may be found in the Microdata User Guide for the NLSCY for cycle 5, page 173-175 (Statistics Canada n.d.b).

Attention score. The attention score included responses to a set of six individual items. The Cronbach’s alpha measure of internal reliability for this score was 0.78. Parents were asked:

How often would you say that (CHILD):

1. Can't sit still or is restless?
2. Is easily distracted, has trouble sticking to any activity?
3. Can't concentrate, can't pay attention for long?
4. Is inattentive?
5. Can not settle on anything for more than a few moments?

Response options were: never or not true, sometimes or somewhat true, and often or very true. Responses were scored 2 for never or not true, 1 for sometimes or somewhat true, and 0 for often or very true.

6. How often does (CHILD): listen well and pay attention?
    (reversed)

Response options were:  never, sometimes, and often. Responses were scored 0 for never, 1 for sometimes, and 2 for often.

Possible scores ranged from 0 (low attention score) to 12 (high attention score).

Work effort score. The work effort score included responses to a set of three individual items. The Cronbach’s alpha measure of internal reliability for this score was 0.64. Parents were asked:

How often does (CHILD):

1. Finish things HE/SHE starts?
2. Persist with solving a problem, even when things go wrong for a while?
3. Make an effort to do something, even if  HE/SHE doesn't feel confident about it?

Response options were:  never, sometimes, and often. Responses were scored 0 for never, 1 for sometimes, and 2 for often. Possible scores ranged from 0 (low work effort score) to 6 (high work effort score).

Curiosity level. Curiosity level was based on the parent’s response to the following question:

• How often does (CHILD): Ask questions or take things apart to find out how they work?

Response options were:  never, sometimes, and often. Curiosity level was analyzed as a two-level variable, not high curiosity (never and sometimes) and high curiosity (often).

Self-control of behaviour score. The self-control of behaviour score included responses to a set of four individual items. The Cronbach’s alpha measure of internal reliability for this score was 0.64. Parents were asked:

How often would you say that (CHILD):

1. Is impulsive, acts without thinking?
2. Has difficulty waiting for HIS/HER turn in games or groups?

Response options were: never or not true, sometimes or somewhat true, and often or very true. Responses were scored 2 for never or not true, 1 for sometimes or somewhat true, and 0 for often or very true.

How often does (CHILD):

3.   Keep HIS/HER temper?
4.   Show self-control?

Response options were:  never, sometimes, and often. Responses were scored 0 for never, 1 for sometimes, and 2 for often.

Possible scores ranged from 0 (low self-regulation of behaviour score) to 8 (high self-regulation of behaviour score).

Cooperative play level. Cooperative play level was based on the parent’s response to the following question:

• How often does (CHILD): Play cooperatively with other children?

Response options were:  never, sometimes, and often. Cooperative play level was analyzed as a two-level variable, not high cooperative play (never and sometimes) and high low cooperative play (often).

Independence in dressing. Independence in dressing was based on the parent’s response to the following question:

• How often does (CHILD): Show independence while dressing?

Response options were:  never, sometimes, and often. Independence in dressing was analyzed as a two-level variable, not high independence in dressing (never and sometimes) and high independence in dressing play (often).

Independence in cleanliness. Independence in cleanliness was based on the parent’s response to the following question:

• How often does (CHILD): Show independence with washing and toileting?

Response options were:  never, sometimes, and often. Independence in cleanliness was analyzed as a two-level variable, not high independence in cleanliness (never and sometimes) and high independence in cleanliness (often).

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Home environment variables

Positive parent-child interaction

The two-level positive parent-child interaction score used was based on responses to a set of five individual items. The Cronbach’s alpha measure of internal reliability for the 5-item score was 0.63. Parents were asked:

1. How often do you praise (CHILD), by saying something like "Good for you!" or "What a nice thing you did!" or "That's good going!"?
2. How often do you and (CHILD) talk or play with each other, focusing attention on each other for five minutes or more, just for fun?
3. How often do you and (CHILD) laugh together?
4. How often do you do something special with (CHILD) that HE/SHE enjoys?
5. How often do you play sports, hobbies or games with (CHILD)?

Response options were: never, about once a week or less, a few times a week, one or two times a day, and many times each day. Responses were scored from 0 for never to 4 for many times each day.  Possible scores ranged from 0  to 20. Positive interaction was analyzed as a two-level variable, not high positive interaction score (at or below the 15th percentile score of 12) and high positive interaction score (above the 15th percentile score, that is, 13 or higher).

Daily reading to the child

Daily reading to the child was based on the parent’s response to the following question:

• How often do you (or your spouse): Read aloud to HIM/HER or listen to HIM/HER read or try to read?

Response options were: rarely or never, a few times a month, once a week, a few times a week, and daily. Responses were scored 0 for less than daily reading and 1 for daily reading.

Daily number use

Daily number use with the child was based on the parent’s response to the following question:

• How often do you (or your spouse): Encourage HIM/HER to use numbers in day to day activities (for example, counting cookies on a plate)?

Response options were: rarely or never, a few times a month, once a week, a few times a week, and daily. Responses were scored 0 for less than daily number use and 1 for daily number use.

Group activities

Parents were asked four questions about their child’s group activities. Activities included: participation in organized sports, participation in unorganized sports, participation in lessons in physical activities, and participation in lessons in the arts. Parents were asked:

In the past 12 months, outside of school hours, how often has (CHILD):

• Taken part in sports with a coach or instructor (except dance, gymnastics, or martial arts)?
• Taken part in unorganized sports or physical activities without a coach or instructor?
• Taken lessons or instruction in other organized physical activities with a coach or instructor such as dance, gymnastics or martial arts?
• Taken lessons or instruction in music, art or other non-sport activities?

Response options were: most days, a few times a week, about once a week, about once a month, and almost never. Responses were scored 0 for not weekly and 1 for at least weekly.

Early childhood education activities age 3

Parents were asked about their child’s involvement in early childhood education activities at the age of 3. The question was:

Does (CHILD) attend the following programs or activities?

1. Nursery school or preschool
2. Play group
3. Drop-in centre
4. Parent and child lessons or program
5. Library storytime or other reading program or book club?

Response options were yes or no for these activities. Responses were scored 0 for no activity and 1 for one activity or more.