How To Properly Test Alt And Title Image Tags

Recently, I began a test of the ALT and Title elements in the img html tag. Here is the breakdown of the testing:

1. Conducting the research by creating a page on the topic of “dogs” that has the same image of a Dalmatian that link to four separate pages. The parent page is only linked to from one page, the other four are linked to from the parent and the same location as the dog page. These pages will be further influenced by placing them into a deeper directory /dogs/.
2. These four links will have the following elements:
• Page One – Link – No Alt – No Title
• Page Two Link – Alt – No Title
• Page Three Link – No Alt – Title
• Page Four Link – Alt – Title
3. These pages will have unrelated but different names.
4. The parent of these pages will be located on a rarely visited page (my html sitemap) by users and crawled regularly by search engine spiders.
5. These pages will contain an H1, H2, H3 and page content. Lorem Ipsen will be used to incorporate the content with keywords added to the content in a consistent manner (same density, character count and placement of keywords).
6. These page will target the keyword “Dalmatian.”
7. When cached by all major engines*, we will conduct a site search for the priority of pages in the SERPs across all engines for “Dalmatian.” This will measure the impact of alt and title elements by seeing which of the pages ranks higher with no external impacts.

* Two notes to this research:
one > the pages within this study were originally published December 11, 2008 and adjustments were made to these pages the following day (due to my lack of spelling prowess) and the original pages were quickly cached by all three engines; and
two > despite returning cached dates of 1/2/2009 and 1/3/2009 MSN/Live Search’s index has failed to pick up the spelling changes that have been made, from “dalmation” to the correct spelling of the canine breed “dalmatian,” except for one of these pages that was reportedly cached on 1/25/2009.

These two notes being taken into account, the results for MSN/Live Search have not been included due to incomplete data. Ask.com was considered for this study, however, it has not, at the time of publication of this study cached any of the tested pages.

This being said, here are the results:

click on the engine name to see the SERPs for the tested query

My initial assumption was that the title element has little, if not no value, however, based upon the results of this study, it appears that this is not the case.

Google

Looking at the results from Google, you can see that the alt element is clearly more valuable than the title element (noting that both pages with alt elements outrank the one with title only). It is also curious that the page with both alt and title elements is the highest ranking page of the four. I would have assumed that this page would have been considered over optimized, but the results differ. The fifth result is interesting, seeing that it only has the target keyword visible once and in the image elements.

Yahoo!

Looking at the result it appears that Yahoo! does not see that utilizing both of these elements are ideal (my assumption is that it appears to be a case of over optimization based upon the fact that the page without either alt or title elements outranks the page with both), however, they put more weight on the title over the alt element. Not having a fifth result was interesting as well, seeing that the targeted keyword was contained within the visible text.

Seeing the results of this study, it is clear to see that Google and Yahoo! assign different values for elements within an image tag, however, it is interesting to see the differences, an apparent over optimization ding from Yahoo! and an increase in ranking from Google. So, with the results in, it looks like if you are optimizing your images for improved performance, the only thing that you can do to positively impact your ranking across both engines would be to utilize only the alt element, however, if you are looking to improve your ranking in Google, you might utilize both alt and title elements to give your page the best chance for ranking better.

I have tried to be as patient as possible with MSN/Live Search to see the impacts, however, I was more excited to release the results of this test than patient. I would absolutely love to hear if you have conducted similar testing and have differing results. I also know that these results will undoubtedly be different after the publication of this post, seeing that additional links will be pointing to these pages and this may/may not skew the ongoing results.

Let me know what you think of my study.

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