Describing the Structure of Grouped Data

Keyword(s):  
2020 ◽  
Author(s):  
Riska Nurhapsari Santoso ◽  
Yudis Satrio Utomo ◽  
Yuliani Luturmasse

Abstract - Statistics is a framework of theories and methods that have been developed to collect, analyze, and write sample data in order to obtain useful conclusions. Statistics is the science of ways of collecting, classifying, analyzing, and searching for information related to the collection of data that investigations and conclusions based on evidence in the form of figures.Based on the results of the study can be concluded as follows: the size of the symptoms of the data center has not been grouped is the data compiled into the frequency distribution so that it does not have class intervals and midpoints of the class. Symptom Size Un-Grouped Data Center The size of the data center included in the statistical analysis is the calculated average (mean), median, mode, and fractil (quartile, decile, percentile)


Author(s):  
Russell Cheng

This chapter examines the well-known Box-Cox method, which transforms a sample of non-normal observations into approximately normal form. Two non-standard aspects are highlighted. First, the likelihood of the transformed sample has an unbounded maximum, so that the maximum likelihood estimate is not consistent. The usually suggested remedy is to assume grouped data so that the sample becomes multinomial. An alternative method is described that uses a modified likelihood similar to the spacings function. This eliminates the infinite likelihood problem. The second problem is that the power transform used in the Box-Cox method is left-bounded so that the transformed observations cannot be exactly normal. This biases estimates of observational probabilities in an uncertain way. Moreover, the distributions fitted to the observations are not necessarily unimodal. A simple remedy is to assume the transformed observations have a left-bounded distribution, like the exponential; this is discussed in detail, and a numerical example given.


2020 ◽  
pp. 1-20
Author(s):  
Chad Hazlett ◽  
Leonard Wainstein

Abstract When working with grouped data, investigators may choose between “fixed effects” models (FE) with specialized (e.g., cluster-robust) standard errors, or “multilevel models” (MLMs) employing “random effects.” We review the claims given in published works regarding this choice, then clarify how these approaches work and compare by showing that: (i) random effects employed in MLMs are simply “regularized” fixed effects; (ii) unmodified MLMs are consequently susceptible to bias—but there is a longstanding remedy; and (iii) the “default” MLM standard errors rely on narrow assumptions that can lead to undercoverage in many settings. Our review of over 100 papers using MLM in political science, education, and sociology show that these “known” concerns have been widely ignored in practice. We describe how to debias MLM’s coefficient estimates, and provide an option to more flexibly estimate their standard errors. Most illuminating, once MLMs are adjusted in these two ways the point estimate and standard error for the target coefficient are exactly equal to those of the analogous FE model with cluster-robust standard errors. For investigators working with observational data and who are interested only in inference on the target coefficient, either approach is equally appropriate and preferable to uncorrected MLM.


Biometrika ◽  
1954 ◽  
Vol 41 (3/4) ◽  
pp. 296 ◽  
Author(s):  
J. M. Hammersley ◽  
K. W. Morton

1997 ◽  
Vol 55 (1) ◽  
pp. 1-8 ◽  
Author(s):  
McKinley L Blackburn
Keyword(s):  

2002 ◽  
Vol 12 (1) ◽  
pp. 1-14
Author(s):  
Yizhe Sun ◽  
Donald A. Godfrey ◽  
Allan M. Rubin

Extracellular single unit recordings were made from regularly discharging medial vestibular nucleus neurons in brain slices from control rats and from rats surviving 7 days after bilateral transection of the inferior cerebellar peduncle. Decreases in firing rate during perfusion with the Îş-aminobutyric acid (GABA) agonists, muscimol (GABA A ) and baclofen (GABA B ), were greater in lesioned rats than in control rats. For the grouped data, the half-maximally-effective concentrations of muscimol and baclofen were 3.2 µM, as compared with 19.6 µM for control, and 0.8 µM, as compared with 2.7 µM for control, respectively. The antagonists bicuculline (GABA A ) and 2-OH-saclofen (GABA B ) only minimally affected the spontaneous firing rates of neurons in lesioned rats, significantly less than in control rats. The data suggest that the decreases of endogenous GABA levels in the medial vestibular nucleus after inferior cerebellar peduncle transection are accompanied by up-regulation of GABA A and, to a lesser extent, GABA B receptors.


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