scholarly journals Using heteroskedasticity-consistent standard error estimators in OLS regression: An introduction and software implementation

2007 ◽  
Vol 39 (4) ◽  
pp. 709-722 ◽  
Author(s):  
Andrew F. Hayes ◽  
Li Cai
Keyword(s):  
Standard Error ◽  
Software Implementation ◽  
Ols Regression ◽  
Error Estimators

Relation between early e-WOM and average TV ratings

2019 ◽  
Vol 32 (1) ◽  
pp. 135-148
Author(s):  
Giwoong Bae ◽  
Hye-Jin Kim
Keyword(s):  
Linear Regression ◽  
Standard Error ◽  
Design Methodology ◽  
Word Of Mouth ◽  
Content Type ◽  
Error Estimators ◽  
Independent Variables ◽  
Advertising Revenue ◽  
Tv Ratings ◽  
Tv Shows

Purpose The purpose of this paper is to investigate the relation between average ratings (viewership) and the volume and valence of electronic word of mouth (e-WOM) for early episodes of TV shows. Design/methodology/approach Linear regression was performed in which the dependent variable is average TV ratings and main independent variables are volume and valence of e-WOM. The study used a Breusch–Pagan test to detect heteroscedasticity. Accordingly, the model is analyzed using heteroscedasticity-consistent standard error estimators. Findings The results show that the volume of the early e-WOM does not significantly contribute to explaining average ratings, but the valence does. Originality/value Because the advertising revenue of television broadcasters is determined according to expected TV ratings, the average ratings should be predicted as early as possible. This study shows that analyzing early e-WOM helps predict average ratings.

The combined Herstmonceux Cambridge Program of optical positions of radio sources

1978 ◽  
Vol 48 ◽  
pp. 155-166 ◽  
Author(s):  
A. N. Argue ◽  
E. D. Clements ◽  
G. M. Harvey ◽  
C. A. Murray
Keyword(s):  
Standard Error ◽  
Unit Weight ◽  
Radio Sources

SummaryAGK3-based optical positions are presented for 38 counterparts of radio sources selected from the catalogue of Elsmore & Ryle. The measurements were made from plates taken with the 13-inch Astrograph, the 26-inch refractor and the 2.5 m (INT) reflector at Herstmonceux, and the 17-inch Schmidt at Cambridge. The standard error for a mean position of unit weight is 0”.11, and the weights range from 3.0 for the brightest sources to 0.5 for the faintest. Comparison with the radio positions shows no significant differences. The effects of applying the Brorfelde corrections to AGK3 are discussed.

Multi-Center Calibration of the Second Reference Material for Thromboplastin, Rabbit, Plain, Coded CRM 149R

1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina
Keyword(s):  
Reference Material ◽  
Standard Error ◽  
Standard Errors ◽  
Sensitivity Index ◽  
Long Term Stability ◽  
Significant Bias ◽  
The Mean ◽  
The Relationship ◽  
International Sensitivity Index

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.

PENILAIAN KESEHATAN TERUMBU KARANG MENGGUNAKAN CITRA SATELIT WORLDVIEW-2 DI PULAU PAHAWANG, LAMPUNG, INDONESIA

2018 ◽  
Vol 2 ◽  
pp. 125
Author(s):  
Lukman Hakim
Keyword(s):  
Error Estimation ◽  
Standard Error ◽  
Red Edge ◽  
Standard Error Estimation

<p>Perairan laut Lampung sebagai bagian kecil dari ekosistem terumbu karang Indonesia terindikasi memiliki tren penurunan kualitas karena aktivitas pelayaran dan pariwisata yang ekstensif khususnya di Pulau Pahawang. Kontrol kondisi terumbu karang pada wilayah ini menjadi kegiatan vital dalam rangkaian konservasi sumber daya laut. Sayangnya, pemetaan kesehatan terumbu karang memerlukan survei detail yang memakan banyak waktu, biaya, dan tenaga. Citra sebagai produk data penginderaan jauh hadir sebagai solusi monitoring terumbu karang secara cepat, murah, dan dalam jangkauan wilayah yang relatif luas. Tujuan dari penelitian ini adalah untuk memetakan kesehatan terumbu karang melalui citra WorldView-2 (WV-2) serta menguji akurasi peta yang dihasilkan. Metode yang digunakan untuk memetakan kesehatan terumbu karang adalah transformasi nilai <em>pixel</em> pada <em>band-band</em> WV-2 menjadi nilai original objek dengan urutan: 1) koreksi atmosfer (<em>Top of Atmospheric Reflectance)</em>, 2) koreksi kilap air (<em>sun glint</em>), dan 3) koreksi kolom air (metode <em>lyzenga</em>) menghasilkan 15 <em>band</em> DII (<em>depth invariant bottom index</em>). Kelima belas <em>band</em> DII tersebut diubah menjadi nilai kesehatan terumbu karang dengan cara regresi antara nilai <em>pixel</em> pada <em>band</em> DII dengan nilai rasio kesehatan terumbu karang aktual yang diperoleh dari proses kalkulasi acak titik foto transek di lapangan. Tiga tipe regresi (linier, eksponen, dan polinomial) dilakukan untuk melihat persamaan terbaik yang bisa digunakan untuk mentransformasi nilai <em>pixel</em> ke nilai kesehatan terumbu karang. Persamaan terbaik kemudian diimplementasikan menjadi model kesehatan terumbu karang untuk kemudian diuji akurasi menggunakan metode <em>Standard Error Estimation</em>. Hasil terbaik diperoleh pada regresi antara rasio kesehatan terumbu karang dengan <em>b</em><em>and</em> DII <em>Coastal Red-Edge</em> dengan koefisien determinasi (R<sup>2</sup>) sebesar 0,6553 dan akurasi pemetaan sebesar 70,191%. Nilai tersebut menunjukan bahwa citra WV-2 memiliki potensi untuk menjadi instrumen monitoring ekosistem marine yang layak.</p><p><strong>Kata Kunci: </strong>Depth Invariant Bottom Index, Kesehatan Terumbu Karang, Lyzenga, Regresi, WorldView-2<strong></strong></p>

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