Type 1 and Type 2 errors, power, and sample size

2012 ◽  
pp. 96-104
Author(s):  
Steve McKillup
Keyword(s):  
Sample Size ◽  
Type 2 Errors

Statistical Power in Psychiatric Research

1986 ◽  
Vol 20 (2) ◽  
pp. 189-200 ◽  
Author(s):  
Kevin D. Bird ◽  
Wayne Hall
Keyword(s):  
Sample Size ◽  
Error Rate ◽  
Statistical Power ◽  
Error Rates ◽  
Psychiatric Research ◽  
Type 1 Error ◽  
Type 2 Error ◽  
Power Analyses

Statistical power is neglected in much psychiatric research, with the consequence that many studies do not provide a reasonable chance of detecting differences between groups if they exist in the population. This paper attempts to improve current practice by providing an introduction to the essential quantities required for performing a power analysis (sample size, effect size, type 1 and type 2 error rates). We provide simplified tables for estimating the sample size required to detect a specified size of effect with a type 1 error rate of α and a type 2 error rate of β, and for estimating the power provided by a given sample size for detecting a specified size of effect with a type 1 error rate of α. We show how to modify these tables to perform power analyses for multiple comparisons in univariate and some multivariate designs. Power analyses for each of these types of design are illustrated by examples.

Errors

2017 ◽  
Author(s):  
Mark Harrison
Keyword(s):  
Emergency Medicine ◽  
Type 2 Errors

This chapter describes types of errors as applied to Emergency Medicine, and in particular the Primary FRCEM examination. The chapter outlines the key details of type 1 errors and type 2 errors. This chapter is laid out exactly following the RCEM syllabus, to allow easy reference and consolidation of learning.

THE EFFECTS OF L1–L2 PHONOLOGICAL MAPPINGS ON L2 PHONOLOGICAL SENSITIVITY

2020 ◽  
Vol 42 (5) ◽  
pp. 1041-1076
Author(s):  
Jeong-eun Kim ◽  
Yejin Cho ◽  
Youngsun Cho ◽  
Yeonjung Hong ◽  
Seohyun Kim ◽  
...  
Keyword(s):  
Response Times ◽  
Lower Sensitivity ◽  
English Sentence ◽  
Real Time Processing ◽  
Phonological Knowledge ◽  
Phonological Sensitivity ◽  
Type 2 Errors ◽  
English I

AbstractThis study examines the effects of asymmetrical mappings of L2 sounds to L1 sounds on real-time processing of L2 phonology. L1-Korean participants completed a self-paced listening (SPL) task paired with a picture verification (PV) task, in which an English sentence was presented word by word along with a picture that matched or mismatched the sentence. In the critical region, an L2 vowel was deliberately replaced with the wrong vowel for two types of English vowel pairs: Type 1: English vowel pairs showing a one-to-one mapping to Korean counterparts (e.g., English: /i/ and /æ/ to Korean /i/ and /æ/, respectively); and Type 2: English vowel pairs showing a two-to-one mapping to a Korean counterpart (e.g., English /i/ and /ɪ/ to Korean /i/). We analyzed response times (RTs) and PV accuracy. Longer RTs were observed for Type 1 errors than Type 2 errors, indicating lower sensitivity to L2 vowels with two-to-one mapping to an L1 vowel. Also, PV accuracy was lower for the sentences containing Type 2 errors. These results suggest that asymmetrical L2-L1 sound mapping can affect learners’ processing of L2 phonological knowledge, which in turn can negatively affect their comprehension.

Type 1 and Type 2 error, power and sample size

2012 ◽  
pp. 105-114
Author(s):  
Steve McKillup ◽  
Melinda Darby Dyar
Keyword(s):  
Sample Size ◽  
Type 2 Error

Bioassessment of stream ecosystems enduring a decade of simulated degradation: lessons for the real world

2012 ◽  
Vol 69 (4) ◽  
pp. 784-796 ◽  
Author(s):  
Robert C. Bailey ◽  
Garry Scrimgeour ◽  
David Coté ◽  
Dan Kehler ◽  
Simon Linke ◽  
...  
Keyword(s):  
Suspended Sediments ◽  
Error Rates ◽  
Reference Condition ◽  
Benthic Macroinvertebrate ◽  
Taxon Richness ◽  
Macroinvertebrate Communities ◽  
Starting Condition ◽  
Type 2 Errors

The effects on benthic macroinvertebrate communities of simulated degradation of streams enabled evaluation of the effects of starting condition, type of degradation, and biota descriptor on the type 1 and type 2 error rates of bioassessment. Benthic macroinvertebrate communities from five reference streams in the Fraser River basin (British Columbia, Canada) were used as the starting conditions of replicated simulations of the effects of suspended sediments in three temporal patterns (none, one-time severe, constant moderate). The dynamics of the simulated stream communities and the type 1 and type 2 errors associated with bioassessments, as described by (i) taxon richness, (ii) EPT (Ephemeroptera, Plecoptera, Trichoptera) richness, (iii) proportion of EPT individuals in the community, (iv) difference in composition from the median reference community (MCDist), (v) Simpson’s diversity, and (vi) Simpson’s equitability, depended on the combination of starting condition, simpact treatment, and the biota descriptor. To reduce type 1 and type 2 errors in bioassessments using the reference condition approach, bioassessment programs should include (i) matching of test and expected reference communities and refinement of the definition of reference condition and (ii) several biota descriptors that include measures of richness, tolerance, and community composition.

STATISTICAL BRIEFING: TYPE 1 AND TYPE 2 ERRORS

2009 ◽  
Vol 50 (2) ◽  
pp. 239-239 ◽  
Author(s):  
CHRISTOPHER R. LAMB
Keyword(s):  
Type 2 Errors

scholarly journals How do Personality and Social Structures Interact with Each other to Predict Important Life Outcomes? The Importance of Accounting for Personality Change

2017 ◽  
Vol 31 (3) ◽  
pp. 279-290 ◽  
Author(s):  
Christopher J. Boyce ◽  
Alex M. Wood ◽  
Liam Delaney ◽  
Eammon Ferguson
Keyword(s):  
Methodological Issue ◽  
Personality Change ◽  
Social Structures ◽  
Life Outcomes ◽  
Personality Psychology ◽  
Personality Changes ◽  
Using Data ◽  
Type 2 Errors

Personality is important for a range of life outcomes. However, despite evidence that personality changes across time, there is a concerning tendency for researchers outside of personality psychology to treat measures of personality as if they are non–changing when establishing whether personality predicts important life outcomes. This is problematic when personality changes in response to outcomes of interest and creates a methodological issue that may result in misleading conclusions. We illustrate this methodological issue and suggest using measures before the outcome takes place to mitigate concerns. We then demonstrate, using data from Germany, that using post–event personality measures, as opposed to pre–outcome measures, to predict both occurrence of, and reactions to, socio–economic events results in inconsistent conclusions in the directions hypothesized and therefore increases the likelihood of Type 1 and Type 2 errors. This has implications for research investigating the importance of personality for psychological, behavioural, and socio–economic outcomes. Copyright © 2017 European Association of Personality Psychology

scholarly journals Invited Commentary: Comparing the Independent Segments Procedure with Group Sequential Designs

2021 ◽  
Author(s):  
Daniel Lakens
Keyword(s):  
Sequential Analysis ◽  
Sequential Designs ◽  
Equivalence Test ◽  
Group Sequential ◽  
Psychological Science ◽  
Type 1 Error ◽  
Software Packages ◽  
Type 2 Errors

Psychological science would become more efficient if researchers implemented sequential designs where feasible. Miller and Ulrich (2020) propose an independent segments procedure where data can be analyzed at a prespecified number of equally spaced looks while controlling the Type 1 error rate. Such procedures already exist in the sequential analysis literature, and in this commentary I reflect on whether psychologist should choose to adopt these existing procedure instead. I believe limitations in the independent segments procedure make it relatively unattractive. Being forced to stop for futility based on a bound not chosen to control Type 2 errors, or reject a smallest effect size of interest in an equivalence test, limit the inferences one can make. Having to use a prespecified number of equally spaced looks is logistically inconvenient. And not having the flexibility to choose α and β spending functions limit the possibility to design efficient studies based on the goal and limitations of the researcher. Recent software packages such as rpact (Wassmer & Pahlke, 2019) make sequential designs equally easy to perform as the independent segments procedure. While learning new statistical methods always takes time, I believe psychological scientists should start on a path that will not limit them in the flexibility and inferences their statistical procedure provides.

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