* Introduction to statistical modelling 2: categorical variables and interactions in linear regression.
- In the first article in this series we explored the use of linear regression to predict an outcome variable from a number of predictive factors. It assumed that the predictive factors were measured on an interval scale. However, this article shows how categorical variables can also be included in a linear regression model, enabling predictions to be made separately for different groups and allowing for testing the hypothesis that the outcome differs between groups. The use of interaction terms to measure whether the effect of a particular predictor variable differs between groups is also explained. An alternative approach to testing the difference between groups of the effect of a given predictor, which consists of measuring the effect in each group separately and seeing whether the statistical significance differs between the groups, is shown to be misleading.
=>初めて, 最初の, 第一の, はじめに, 最初, 第1
Overview of noun first
The noun first has 6 senses (first 4 from tagged texts)
1. (9) first, number one -- (the first or highest in an ordering or series; "He wanted to be the
first")
2. (5) first, number one, number 1 -- (the first element in a countable series; "the first of the
month")
3. (1) beginning, commencement, first, outset, get-go, start, kickoff, starting time, showtime,
offset -- (the time at which something is supposed to begin; "they got an early start"; "she knew
from the get-go that he was the man for her")
4. (1) first base, first -- (the fielding position of the player on a baseball team who is stationed
at first of the bases in the infield (counting counterclockwise from home plate))
5. first, first-class honours degree -- (an honours degree of the highest class)
6. first gear, first, low gear, low -- (the lowest forward gear ratio in the gear box of a motor
vehicle; used to start a car moving)
Overview of adj first
The adj first has 6 senses (first 5 from tagged texts)
1. (232) first -- (preceding all others in time or space or degree; "the first house on the right";
"the first day of spring"; "his first political race"; "her first baby"; "the first time"; "the
first meetings of the new party"; "the first phase of his training")
2. (61) first, 1st -- (indicating the beginning unit in a series)
3. (4) inaugural, initiative, initiatory, first, maiden -- (serving to set in motion; "the
magazine's inaugural issue"; "the initiative phase in the negotiations"; "an initiatory step toward
a treaty"; "his first (or maiden) speech in Congress"; "the liner's maiden voyage")
4. (4) beginning, first -- (serving to begin; "the beginning canto of the poem"; "the first verse")
5. (3) first, foremost, world-class -- (ranking above all others; "was first in her class"; "the
foremost figure among marine artists"; "the top graduate")
6. first -- (highest in pitch or chief among parts or voices or instruments or orchestra sections;
"first soprano"; "the first violin section"; "played first horn")
Overview of adv first
The adv first has 4 senses (first 4 from tagged texts)
1. (58) first, firstly, foremost, first of all, first off -- (before anything else; "first we must
consider the garter snake")
2. (40) first, for the first time -- (the initial time; "when Felix first saw a garter snake")
3. (9) first -- (before another in time, space, or importance; "I was here first"; "let's do this
job first")
4. (4) foremost, first -- (prominently forward; "he put his best foot foremost")
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