20241019 - hypothesis vs prediction

Author: isaactpetersen

writing.Rmd

@@ -20,6 +20,13 @@ Below are writing guidelines for the Developmental Psychopathology Lab:
 1. Provide and interpret effect sizes (e.g., *r*s, *d*s, betas), and not just statistical significance.
 1. Report numbers to two decimal places; report *p*-values to three decimal places.
 1. Per APA style (4.22), "while" and "since" should be reserved strictly for their temporal meaning; for non-temporal meanings, use terms such as "whereas" and "because", respectively.
+1. Know the difference between a "hypothesis" and a prediction—and use them correctly ([Eastwell, 2014](https://files.eric.ed.gov/fulltext/EJ1057150.pdf); archived at https://perma.cc/8EX4-8JYN).
+A hypothesis is a proposed explanation.
+A prediction is the expected result of a test that is derived, by deduction, from a hypothesis or theory.
+Here is an example of a hypothesis and the resulting prediction:
+<br>
+"We <u>*hypothesize*</u> that poor language skills leads to physical aggression because of difficulties in (a) using language as a self-regulatory tool resulting in dysregulated behavior, in (b) interactions with peers leading to peer rejection and resulting frustration, and in (c) communicating one's needs and having one's needs met leading to frustration and to resorting to other methods to achieve one's goals.
+If the hypothesis is true, we <u>*predict*</u> that children with poorer language skills will show more externalizing behavior than children with greater language skills."
 1. Per [author guidelines of *Child Development*](https://www.srcd.org/research/journals/child-development/child-development-submission-guidelines#APA) (archived at https://perma.cc/7P53-DLVT), use "relationship" to describe social bonds between people, not variables; to describe associations between variables, use "association", "relation", "covariation", or "correlation".
 1. Report relevant aspects of [reliability](https://isaactpetersen.github.io/Principles-Psychological-Assessment/reliability.html#typesOfReliability) (e.g., [internal consistency](https://isaactpetersen.github.io/Principles-Psychological-Assessment/reliability.html#internalConsistency-reliability), [inter-rater](https://isaactpetersen.github.io/Principles-Psychological-Assessment/reliability.html#interrater-reliability), [test–retest](https://isaactpetersen.github.io/Principles-Psychological-Assessment/reliability.html#testRetest-reliability)/cross-time [stability](https://isaactpetersen.github.io/Principles-Psychological-Assessment/reliability.html#stability) and [repeatability](https://isaactpetersen.github.io/Principles-Psychological-Assessment/reliability.html#repeatability)) and [validity](https://isaactpetersen.github.io/Principles-Psychological-Assessment/validity.html#measurementValidity) (e.g., [convergent](https://isaactpetersen.github.io/Principles-Psychological-Assessment/validity.html#convergentValidity), [discriminant](https://isaactpetersen.github.io/Principles-Psychological-Assessment/validity.html#discriminantValidity), [incremental](https://isaactpetersen.github.io/Principles-Psychological-Assessment/validity.html#incrementalValidity), [criterion-related](https://isaactpetersen.github.io/Principles-Psychological-Assessment/validity.html#criterionValidity)) for the measures you are using, including based on evidence from prior studies and based on estimates in the present study—in particular, those that are most relevant to the particular population, context, purpose, etc.
 1. When referring to reliability, validity, or stability, specify the aspect(s) of reliability/validity/stability you are referring to.