Enum: Direction¶
How a term entered or came out of an analysis, using one vocabulary for every term type. Both a categorical level on the plus side of a comparison and a continuous term with a positive coefficient are positive. The referenced term's type distinguishes them. For a cell over a product term, this field gives the interaction coefficient's sign, not either component's slope.
It is a sign, not a magnitude: numeric contrast weights are never recorded, and a contrast whose magnitudes matter keeps them in Analysis.definition. There is no value for a zero weight either -- a level the contrast did not weight has no Cell at all.
Only positive and negative are directional. A cell can record no sign three ways -- undirected, held, or extraction_status: not_reported -- and choosing between them is the decision rule in extraction-readme.md §2.
Permissible Values¶
| Value | Meaning | Description |
|---|---|---|
| positive | None | A level on the plus side of the comparison, or a coefficient under which the ... |
| negative | None | A level on the minus side of the comparison, or a coefficient under which the... |
| undirected | None | The test yields no per-level sign, so there is none to report |
| held | None | A level the contrast was taken within, which appears on both sides of t... |
Slots¶
| Name | Description |
|---|---|
| value |
Identifier and Mapping Information¶
Schema Source¶
- from schema: https://neurostuff.org/schemas/neuroimaging-study-extraction
LinkML Source¶
name: Direction
description: 'How a term entered or came out of an analysis, using one vocabulary
for every term type. Both a categorical level on the plus side of a comparison and
a continuous term with a positive coefficient are `positive`. The referenced term''s
`type` distinguishes them. For a cell over a **product** term, this field gives
the interaction coefficient''s sign, not either component''s slope.
It is a sign, not a magnitude: numeric contrast weights are never recorded, and
a contrast whose magnitudes matter keeps them in `Analysis.definition`. There is
no value for a zero weight either -- a level the contrast did not weight has no
`Cell` at all.
Only `positive` and `negative` are directional. A cell can record no sign three
ways -- `undirected`, `held`, or `extraction_status: not_reported` -- and choosing
between them is the decision rule in extraction-readme.md §2.'
from_schema: https://neurostuff.org/schemas/neuroimaging-study-extraction
rank: 1000
permissible_values:
positive:
text: positive
description: A level on the plus side of the comparison, or a coefficient under
which the measure rises as the term rises.
negative:
text: negative
description: A level on the minus side of the comparison, or a coefficient under
which the measure falls as the term rises.
undirected:
text: undirected
description: 'The test yields no per-level sign, so there is none to report. An
F or chi-square over a factor compares that factor''s levels against each other
and returns one statistic for the set: every one of its levels takes a cell
with this value, and a multi-degree-of-freedom interaction F takes it on the
cell over the product column.
Not `extraction_status: not_reported`: the sign is not missing from the page,
it is absent from the test, so there is something to record rather than nothing.
The post-hoc contrast that would supply one is a different Analysis.'
held:
text: held
description: 'A level the contrast was taken *within*, which appears on **both
sides** of the comparison and so has no net sign -- "patients versus controls,
in the task condition" has task on the plus side and the minus side at once.
Cell that one level and leave its factor''s other levels **absent**, where an
undirected test cells every level.
No report, however complete, could sign this cell, which is what separates it
from both unsigned neighbours: `undirected` is a test that produces no sign,
a sign the page withheld is `extraction_status: not_reported`, and this is a
sign that is not defined. A cell that names no level -- on a slope or a product
column -- can never sit on both sides, so it can never take this value.'