Google Scholar: CAPTCHAS

Publish or Perish tutorial

Anne-Wil Harzing - Sat 6 Feb 2016 16:10 (updated Sat 15 Apr 2023 07:38)

Publish or Perish is doing everything to limit burdening Google Scholar with too many queries.

We keep results in the cache, so there is no need to query Google Scholar if you run the same search repeatedly within a short period.
We limit the request rate so that if you perform queries that yield many results (several hundred or more) or issue a number of queries in short succession, the request rate limiter will insert progressively longer delays to keep the overall request rate within acceptable limits.
We alert you if your request rate is running too high.

CAPTCHAS are unavoidable at very high request rates

However, we cannot avoid that sometimes Google Scholar will present you with a CAPTCHA that you need to solve to verify that you are a human and not a robot. This is how this will look.

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How to "solve" captchas

After clicking the box, you will be presented with either a range of images from which you need to select a specific type of image or a squiggly word that you need to type into a box. Once you have identified the correct images (usually street signs, oceans, boats, homes, cars, food etc.), you will normally get a second set of images. If you identify both sets correctly, your search will proceed as normal.

How to prevent captchas

We realise this is very annoying, but there is really nothing we can do about this. You can avoid this by not running too many queries in a short space of time and being smart in your queries so that you do not get hundreds of irrelevant results.

In extreme cases Google might return an HTTP status code 429 (Too Many Requests); in that case you will have to refrain from using Google Scholar for 24 hours or so before retrying.

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Anne-Wil Harzing is Emerita Professor of International Management at Middlesex University, London. She is a Fellow of the Academy of International Business, a select group of distinguished AIB members who are recognized for their outstanding contributions to the scholarly development of the field of international business. In addition to her academic duties, she also maintains the Journal Quality List and is the driving force behind the popular Publish or Perish software program.

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