Questions on Meva

Missing Data

Saving Problems: I'd like to save Meva's result onto my hard drive to access the page even when not connected to the Internet. But when I try to save the file I get a browser error.

This odd behaviour can occur with different browsers and versions whilst saving the file:

Internet Explorer. If you get an alert message warning that the page may not be saved properly, simply ignore that. You may also select the “Do not display this message again” checkbox to prevent the message from appearing in the future.

Now Explorer will show you the Save As dialog box. Make sure Explorer suggests “Web Page, HTML only” as file type. Enter a name for the file to save and select OK.

Note: If Explorer suggests “Text File”, do not try to change the proposed file type, otherwise you browser may hang! Instead cancel this window and select the Save As command once more. Now Explorer should suggest “Web Page, HTML only” as file type. This odd behaviour should only happen the first time you want to save a form result in an Explorer session and is a bug in earlier Explorer Versions.

Netscape/Mozilla. If you get an error message: “The link could not be saved. The web page might have been removed or had its name changed.” you may copy the source code of the Meva result into a text file and rename the file extension to .HTML then. This is a bug in some versions of Netscape and Mozilla. Follow this guideline to get the file saved:

  1. Press Ctrl-U (View source code).
  2. Press Ctrl-A (Select all text).
  3. Press Ctrl-C (Copy selected text into clipboard).
  4. Open a text editor of your choice e.g. Notepad. Avoid text processors which use formatting e.g. MS Word or Wordpad.
  5. In the editor, press Ctrl-V (Insert selected text from clipboard).
  6. Save the document with the extension “.htm” or “.html”.

Opera. When you submit the form to Meva with the form option Text, Opera may ask if it shall open or save the file. Some Opera Versions assume per default text data (generated by a CGI) to be of MIME type “application/octet-stream”. This is of little sense. To suppress that, select below File | Preferences | File types the option Determine action by MIME type.

Request Too Large: When I consult Meva, my browser says “413 Request entity too large”.

You have exceeded the maximal input size Meva admits. To protect the network, Meva does not allow huge input file sizes. Possible workarounds:

  1. Perform a PubMed query with more specific search patterns to receive less data.
  2. Use PMComp for compression before sending the data to Meva.

MS Access: When I try to import a Meva text format result, MS Access returns the following error: “The Microsoft Jet database module could not find object xxx” or “Invalid table name”.

Avoid to save your Meva result with more than one dot in the file name. A file name like result.txt would be fine.

MeSH Count Differences: I selected MeSH terms in Meva's consultation form and an asterisk as filter expression to retrieve only major topics as well as to exclude generic terms. Therefore the count of filtered MeSH terms should be equal to the cumulated MeSH tree frequency - but it differs slightly. Why?

This can happen to articles indexed by the NLM with terms created after the yearly publication of the MeSH tree. Another reason might be sending an older PubMed result file (with possibly outdated terms) to Meva. You can determine these outliers in the details table by checking MeSH-Codes in Meva's form; the outliers will appear without a code.

Layout and Language

No Background Printing: On Meva's printout, contingency cell colors are dropped.

When you print out Mevas result page you may notice that some items on the page disappear like table backgrounds. Mevas result page contains background colours, and these are the items that are disappearing. Background printing is the setting on your Internet browser software that decides whether to print these background items or not.

Choosing not to print background images and colours saves on ink, and is a preferred option for many considering the cost of cartridges. However, to get the histograms on paper you have to print Mevas result page with all background items.

Please check the option for background printing in your web browser. You can find it in

BrowserMenu
OperaFile | Print options
Internet Explorer 6 for WindowsExtras | Internet Options | Advanced | Printing | Print background colors and pictures
Internet Explorer 8 for WindowsFile | Page Setup | Print background colors and pictures
Internet Explorer for Macintosh (OS9.2 and X)File | Print | Copies & pages (OS9.2) or General (X) | Internet Explorer | Print background
NetscapeFile | Page Setup

Netscape 4 however still has enormous problems with that, so an upgrade to a newer version or the use of Opera resp. Internet Explorer would be a better solution. For instructions relating to other browser software not covered here please consult documentation supplied with your computer.

Printer Resolution: Meva's printout shows rasterized histogram bars and contingency cells.

Increase the print density of your printer (say 600 dpi or more) or change the printing mode of your printer from raster to halftone processing.

Before printing, you should always use the Print Preview Command of your browser before printing pages to get an idea of print layout and font sizes. Afterwards, you can use the Page Setup Command of your browser to change the size of all the margins of the printed page. Apart from that, you can reduce the font size of the printout:

BrowserMenu
OperaFile | Print Options | Scale print to
Internet ExplorerView | Font Size
NetscapeFile | Print Preview | Scale: Shrink to Fit

If both still results in printing cut-off, change the printing orientation from Portrait to Landscape. Besides, you can decrease the top count in Meva's form.

Font Size: The font size of Meva's result is too small/large and hard to read.

Poor eyesight? Fuzzy monitor? This Web site is designed to support you. Every page on this Web site supports text scaling:

BrowserMenu
OperaSimply press the Plus button once or multiple times.
Internet Explorer 6View | Font Size
Internet Explorer 7 and aboveView | Font Size or simply click the Plus symbol.
NetscapeView | Increase Font
Netscape 6 and aboveView | Font Size

Netscape 4 CSS Error: Netscape shows ripped text with abnormal font sizes.

Netscape 4 has enormous problems to process CSS format assignments in a proper way and many bugs as well. Again, upgrade to a more recent Netscape version (V.6 should be fine) or use Opera resp. Internet Explorer.

Mozilla 7 List Error: Mozilla 7 seems to print an incomplete details list.

This seems to be a bug in Mozilla 7. Try to use recent Opera or Internet Explorer versions for printing purposes.

Weird looking Text Result: I have chosen Text as data output format. The data Meva returned do not look tabularly but ripped instead.

That's ok. The fields of the returned data are separated by tabs, which looks weird inside a browser. But don't worry, each database will correctly import that data. If you only to intend to view these data, load that file into a text processor which allows to set personal tab stop positions.

Language: Why do I get a wrong language version of this site and how can I change it?

This server supports automatic language negotiation for English and German. Entering f.i. http://meva.med-ai.com/ oder http://www.med-ai.com/meva/faq into your browser address field you should get dependant from your browser language settings the appropriate English or German web page. In case this automatism fails you can set the required web page language by selecting the appropriate language link in the navigational bar of the web page.

Possible reasons for the automatic language negotiation to fail:

  1. Improperly configured browser.
  2. Broken or a misconfigured proxy. This is a growing problem as more ISPs see caching as a way of decreasing net traffic.
  3. Problems with the webserver itself.

Now let's talk about 1, the most common reason:

A web server with the capability of content negotiation according to RFC 2616 determines the user preferred language of a web page by the user language settings of your browser. These settings are either derived from the language and locale settings of the operating system or the user has been asked for it during the browser installation. Most browsers allow you to change these settings. You should set the preferred language to all the languages you speak, ordered by your preference.

BrowserMenu
OperaTools | Preferences | General | Language
Internet ExplorerTools or View or Extras | Internet Options | General | Languages
NetscapeEdit | Preferences | Navigator | Languages

Some language settings are listed below:

CodeLanguage
enGeneric English
en-USEnglish, USA
en-GBEnglish, Great Britain
en-AUEnglish, Australia
deGeneric German
de-DEGerman, Germany
de-CHGerman, Switzerland
Etc.

So an English speaker should have at least “en” within this list. Do not add country extensions to a language as in “en-US” unless you have good reason! The reason is if your browsers requests a file in “en-US” and a RFC-compliant server has this file only in “en”, he will not return the English file to you but instead will give an error 406 - Not acceptable or a web page in its fallback language (f.i. in Spanish or Chinese). This sounds illogical, but that is the procedure according to the RFC. Besides, you will hardly find any web server out there which will deliver different web pages particularly for US users or for British users. Moreover, your privacy expectations regarding your linguistic preferences or ethnic membership may be concerned. For a more in-depth discussion of this issue, see RFC 2616 section 15.1.4.

Conclusion: Check the language settings of your browser. Make sure your preferred languages are set without any country extension, ordered by your preference.

Note 1: Ignoring the web standard, IE 7 and above set mistakenly a country extension by default depending from your operating systems language settings. According to the Windows Internet Explorer Weblog, this IE »feature« shall add international support for IE or in other words, reveal more information about the user in every request to all servers which are accessed. Combined with geo-localisation of IP adresses it will improve the identification of users.

Note 2: With Netscape 4 (does anybody still use it?) you need to make sure you select the language from the available choices. A number of people reported problems because they typed in the language by hand.

Note 3: According to RFC 2616 section 14.4, user language and web page language must match exactly: so “en” matches “en”, but not “en-US”. The web server Apache 2 and above added exceptions to this automatic content negotiation rule to allow graceful fallback when language negotiation fails to find a match: In case the server finds no appropriate language, it can ignore the country extension thus enabling a client with “en-US” to get an “en” document. Since not all web servers allow such exceptions and since of the privacy considerations mentioned above it is still advisable to avoid country extensions.

Scripting

Scripting: Internet Explorer always asks me: “A script is running. Will you continue to run the script?” (or similar)

You can answer to that question safely with Yes. The script IE is referring to is only for more user's convenience. It checks if you have filled in the compulsory form fields (f.i. the file name) or gives some consultational hints. The form also works fine without the script, so can you enter even No and Meva would work anyway. If you like, you can tell Internet Explorer to suppress further questions (Extras | Internet Options | Security).

If you get IE warnings in the information bar opening a locally saved Meva result, you can enable execution of active content inside local files (Extras | Internet Options | Advanced) to get rid from repeated warnings. Meva generates links from the bibliographic fields inside a result to PubMed to allow a stepwise refined search. To reduce the file size of a Meva result file, Meva generates these links with JavaScript instead of normal HTML links. If you do not need links, you can ignore that.

Processing Speed

Slow Request: My browser needs very long to submit the form.

Either you tried to send a huge file to Meva, you have a slow net connection or the server is overburdened. In the 1st case there's help: You can compress the file with PMComp before sending it to Meva. This will accelerate your consultation.

Slow Result: My browser needs very long to show the Meva result.

Especially if you combine fields which occur usually multiple time inside an article like MeSH Terms or Authors, the number of returned details table cells will explode in a combinational way. There are several workarounds you can use; start with the first one and if this is not sufficient, try the next:

  1. Use more specific filters inside the Meva consultation form
  2. Use higher Minimal Frequencies
  3. Leave the link restrictor empty - this will deactivate the links and reduce both result size and response time of your browser
  4. Do not enter a 2nd search field and leave the Always show PMID option empty as well
  5. Switch off the details section
  6. Select text as data format