BUG REPORT: Changing sort order caused 44% of search results to disappear!

[gpspilot]

Here's my search:

gallium -(nitride,arsenide,argon,fet,postcard,citroen,usb,paint,charger,empty,laptop,wolf,hardcover,vlsi)

"Include description" is not checked.  This results in a URL of

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=gallium+-%28nitride%2Cars...

This showcases several bugs in eBay search:

1.  Even though "Include description" is not checked,

    - The first page of search results (items 1 - 240) contains several items that don't have keyword "gallium" in the title.

    - On the second page (items 241 - 284), 93% of the items don't have keyword "gallium" in the title.  

2.  Even though "paint" is one of the excluded keywords, the search results do contain items with "paint" in the title.

3.  Worst of all, if sorted by "Best Match," eBay shows 284 results.  If you change the sort order to "Price + Shipping: lowest first" (which is often the most sensible way to search), the number of search results drops to 160!  44% of the search results disappeared – including the one I was most interested in buying!   I thought I was going mad until I figured out what it was doing.  Changing your sort order shouldn't cause ANY search results to disappear – let alone 44% of them!!

If only eBay provided a way for users to report bugs.  (This forum doesn't count.  I've never seen their engineers take action on a problem reported in this forum.)   Over the years, I could have helped them fix dozens of very serious bugs, which must have cost them billions in sales.

[eburtonlab]

eBay by default matches keywords to words in the item title and also the item-specifics. If you see results lacking matching keywords there, eBay may be matching synonyms of your keywords. If you only want to see exact, literal matches, try putting one of your search keywords in quotes -- though if you are using advanced search commands like exclusions or parentheses to search for Boolean OR terms, you should not see any keyword substitutions.

The "Price plus shipping: lowest first" sort order provides filtered results -- often drastically filtered. And the option to "see more results" may not always be shown as it should. The filtering may vary depending on the keywords used.

If you encounter a drastically filtered result for a keyword search using a desktop browser, you should be able to use the "Feedback" link in the lower right corner of the search results to provide feedback on your search to eBay developers. The more users provide info, the more likely something is to be done about the over-filtration problem.

You can avoid that problem entirely by using a different sort order.

If you have few results, try sorting by "highest first", then starting at the end of the results, scroll up instead of down. This also avoids the problem of variation listings with low-cost variations appearing at the top of the lowest-first sort.

If you have a bookmarked or saved lowest-first search that you use a lot, you can avoid the filtration by adding the following to the end of the search URL, then saving the resulting search:

&_blrs=recall_filtering

[gpspilot]

Thanks.  I tried your suggestion and here are the results.

• Sort by "Best Match":  284 results

• Sort by "Price + Shipping: lowest first":  160 results

• Sort by "Price + Shipping: lowest first" with recall_filtering added to URL:  192 results.  (So it weakly mitigated the disappearing-results problem.  This is madness.  The item I was most interested in buying is not one of the 32 results that was restored by recall_filtering.)

I have used the "Feedback" link many times, but today eBay is not providing that link to me.

I figured out why the search for "gallium" is returning lots of romance novels by Vanessa Riley .  Buried down under "Item Specifics," her publisher is "Gallium Optronics."  Yeah, those are some relevant search results! </sarcasm> SMH.  Why does search have an "Include description" checkbox, if eBay is just going to ignore the user's wishes there?

[selsa84]

Search has been an issue for a while. Searched "Alabama map" 2 days ago and a bumper sticker of a Texas college was third from the top.  Sorry but that should not happen. 

[eburtonlab]

Why does search have an "Include description" checkbox, if eBay is just going to ignore the user's wishes there?

The "include description" option searches the entire body of the description, not just the item-specifics.

If your search is turning up romance novels, you may want to either limit the category you are searching, or add some additional keywords that are unlikely to be present in the listings you are not interested in. In some cases, splitting one large search into two smaller searches might help.

Are you looking for actual metallic Gallium? If so, try this:

https://www.ebay.com/sch/i.html?_from=R40&_nkw=gallium+metal+-%28nitride%2Carsenide%2Cargon%2Cfet%2C...

[gpspilot]

Yes, I'm looking for gallium metal, but some sellers don't put "metal" in the title, so I didn't want to exclude those by adding the keyword "metal."

And a problem with restricting search to a certain category, is that many sellers miscategorize their items.  For example, this gallium seller put it in the "Bicycle frames" category, of all places!   https://www.ebay.com/itm/225645909928

Yes, if sellers were perfect, things would be a lot easier.

[eburtonlab]

There are two basic ways a search can go wrong: false positives and false negatives.

False positives are when the search returns items that may meet your search criteria but are not really of interest. Sometimes referred to as Type I errors.

False negatives are when the search fails to return an item you would be interested in buying, but for some failure of the search or the search terms. Sometimes referred to as Type II errors.

Generally it is easy to minimize either false positives or false negatives when searching. But minimizing both at the same time is a challenge. It may be useful to have separate searches: one that is guaranteed to only find what you are looking for, and another that is guaranteed not to miss what you are looking for. The former should provide few results that are quickly scanned for good deals; the latter should provide many results and may need to be combed through more carefully to find items the first search misses.

If not all sellers selling metallic Gallium use the keyword "metal" in their titles or item specifics, there may be other words commonly associated with those types of listings. For instance:

https://www.ebay.com/sch/i.html?_nkw=gallium+%28metal%2Cmetallic%2Cpure%2Celement%2Celemental%29+-%2...

[gpspilot]

I see what you did there.  It has to match at least one of the five keywords (metal,metallic,pure,element,elemental) to be in the results.  

That results in a pretty good search.  Although it is still finding the "BAZINGA GEEK T-Shirt," LOL.

[eburtonlab]

You can use additional exclusions to eliminate other unwanted results, as long as you are reasonably sure those keywords do not appear in any wanted results:

https://www.ebay.com/sch/i.html?_from=R40&_nkw=gallium+%28metal%2Cmetallic%2Cpure%2Celement%2Celemen...