Calculate world normalised citation count indicators (for multiple fields and/or years)

For world normalised statistics, a folder of files with structured names is needed.

Select Calculate MNLCS, gMNCS and NPC for a set of any tab-delimited files (multiple files with structured names) from the Reports menu. From the dialog box that appears next, select the folder containing the WoS or Scopus files in structured name format and click OK.

You will be asked to enter the number of the column containing the indicator data. For this, the citation count column is needed. Within WoS this is called TC (Times Cited) and is normally the 43rd column. If you are using WoS, check that column number 43 in the dialog box is TC, enter 43 in the textbox and click OK. The report should now be created and saved to a file in the same folder called Report.txt. A second file called AllData.txt should also be created but this isn’t needed now. The report is copied below, with the table parts at the end formatted in Excel and edited for ease of reading here.

The top part of the report (below) is includes some results for individual files and some world-normalised results. These are MNLCS (Mean Log-transformed Normalised Citation Scores) and NPC (Normalised Proportion Cited) values, with confidence intervals.

MNLCS is the average number of log-transformed citations for the group, divided by the average number of log-transformed citations for the corresponding world set. Values higher than 1 indicate that the citation counts for the group tend to be above the world average and values below 1 indicate that citation counts for the group tend to be below the world average. Two confidence intervals are reported for MNLCS but the sample confidence intervals should always be used unless making the assumption that the world file contains a complete set of all the world’s articles from the field and year.

NPC is the proportion of articles cited for the group, divided by the corresponding world proportion of cited articles for the same field and year. Values higher than 1 indicate that the proportion of cited articles for the group is above the world average and values below 1 indicate that the proportion of cited articles for the group is below the world average. These figures can be ignored for the World groups because they are always 1.

If a group confidence interval for any MNLCS or NPC does not contain 1 then this gives statistical evidence that its value differs from the world average of 1. This is because both indicators are designed so that the world average is always exactly 1.

In the report below, Spain is cited slightly above the world average in the Biochemistry Molecular Biology Alcohol 2012 set because MNLCS=1.014159 but the MNLCS sample confidence interval (0.933267, 1.100195) contains 1 so the difference is not statistically significant. Spain is also slightly above the world average for the proportion cited in the Chemistry Alcohol 2012 set because NPC=1.072003 and the NPC confidence interval (1.019555, 1.127149) does not contain 1 so the difference is statistically significant.

World File: Biochemistry Molecular Biology Alcohol  2012
       Records                      : 500
       Arithmetic mean of raw data  : 15.734000
       Geometric mean (95%CI) of raw data   : 7.565299 (6.688286, 8.542353)
       Mean (95%CI) of ln(1+raw data)   : 2.147719 (2.039698, 2.255740)
       Proportion (95%CI) non-zero      : 0.870000 (0.837679, 0.896679)
       MNLCS - mean (95%CI) of world normalised ln(1+raw  data) [population version] : 1.000000 (0.949704, 1.050296)
       MNLCS - mean (95%CI) of world normalised ln(1+raw  data)     [sample version] : 1.000000  (0.931272, 1.073800)
       NPC - world normalised proportion (95%CI) cited  (non-zero): 1.000000 (0.953415, 1.048861)
Group file: Spain. In set: Biochemistry Molecular  Biology Alcohol 2012
         Records   :  193
         Arithmetic mean     : 12.606218
         Geometric mean (95%CI) of raw data   : 7.829769 (6.664784, 9.171823)
         Mean (95%CI) of ln(1+raw data)   : 2.178129 (2.036636, 2.319621)
         Proportion non-zero (95%CI)      : 0.932642 (0.888182, 0.960217)
         MNLCS - mean (95%CI) of world normalised ln(1+raw  data) [population version] : 1.014159 (0.948279, 1.080040)
         MNLCS - mean (95%CI) of world normalised ln(1+raw  data)     [sample version] : 1.014159  (0.933267, 1.100195)
         NPC - world normalised proportion (95%CI) cited  (non-zero): 1.072003 (1.019555, 1.127149)
World File: Chemistry Alcohol 2012
         Records                       : 500
         Arithmetic mean of raw data  : 15.376000
         Geometric mean (95%CI) of raw data   : 7.752018 (6.937804, 8.649750)
         Mean (95%CI) of ln(1+raw data)   : 2.169284 (2.071637, 2.266932)
         Proportion (95%CI) non-zero      : 0.928000 (0.901932, 0.947542)
         MNLCS - mean (95%CI) of world normalised ln(1+raw  data) [population version] : 1.000000 (0.954986, 1.045014)
         MNLCS - mean (95%CI) of world normalised ln(1+raw  data)     [sample version] : 1.000000  (0.938274, 1.065786)
         NPC - world normalised proportion (95%CI) cited  (non-zero): 1.000000 (0.966312, 1.034863)
Group file: Spain. In set: Chemistry Alcohol 2012
         Records   :  282
         Arithmetic mean     : 14.709220
         Geometric mean (95%CI) of raw data   : 9.792877 (8.737366, 10.962804)
         Mean (95%CI) of ln(1+raw data)   : 2.378886 (2.275971, 2.481802)
         Proportion non-zero (95%CI)      : 0.971631 (0.945029, 0.985556)
         MNLCS - mean (95%CI) of world normalised ln(1+raw  data) [population version] : 1.096623 (1.049180, 1.144065)
         MNLCS - mean (95%CI) of world normalised ln(1+raw  data)     [sample version] : 1.096623  (1.030278, 1.167420)
       NPC - world normalised proportion (95%CI) cited  (non-zero): 1.047016 (1.015084, 1.079954)

Whilst the top part of the report contains the results for individual sets, the bottom part (below, with table headings edited to fit on the page) contains the results after appropriately aggregating all field/year sets. For this combined set, the Spain MNLCS value is above the world average at 1.06 and its confidence interval also excludes the world average of 1, and so within the combined set of 475 articles there is statistically significant evidence that Spanish alcohol research from 2012 was cited at a rate above the world average. The same is true for the NPC value, 1.059, for Spain and so a statistically significantly higher proportion of Spanish alcohol research from 2012 were cited than the world average.

The mean Normalised Log-transformed Citation Scores (MNLCS) in the table below are the best to use to compare the group overall with the world average if there are multiple different world averages (e.g., different fields and/or years).
For each group they are the average of ln(1+c) values, divided by the world average ln(1+c) for the file (e.g., field and year).
The world average MNLCS should always be 1.
MNLCS values above 1 indicate that the group average is higher than the world average; MNLCS values below 1 indicate that the group average is lower than the world average.
WARNING! MNLCS POPULATION confidence limits below are optimistic because they do not take into account the variability in the world average value.
  - Please use only the MNLCS SAMPLE confidence limits. These are adjusted from the population limits using the weighted average Feiller Expansion calculation.
  - NaN in the Sample confidence limits mean that these are impossible to calculate and are effectively infinite.

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Group N     MNLCS L95Sample   U95Sample   L95Pop      Upper95Pop
World 1000  1     0.953825    1.049397    0.966268    1.0337318
Spain 475   1.06  1.011297    1.118346    1.024124    1.1021043
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Proportion non-zero calculations - these are *biased* estimators and should normally be ignored because different fields and years can have different natural proportions of cited articles.

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Group N     PropNonzero       Lower95     Upper95
world 1000  0.899000          0.8780      0.916176
Spain 475   0.955789          0.9332      0.970904
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Field equalised proportion non-zero calculations - all group sample sizes are set to the arithmetic mean sample size for sets with at least one publication.

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Group N     PropNonzero Lower95     Upper95     NPC   Lower95     Upper95
world 1000  0.899000    0.878770    0.916176    1.00  0.971127    1.029732
Spain 475   0.952137    0.929048    0.967971    1.059 1.029094    1.089994
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