Searching by title on the advanced search method doesn't restrict the results to posts containing the specified text as a word or even substring. Varying the string has some influence, but I can't figure out what.
https://api.stackexchange.com/2.1/search/advanced?order=desc&sort=creation&title=gobbledygook&site=stackoverflow (excerpted):
{
"items": [
{
"question_id": 11639593,
"last_edit_date": 1343165944,
"creation_date": 1343165332,
"last_activity_date": 1343165944,
"score": 0,
"answer_count": 0,
"title": "UILabel does not display all the text",
"tags": [
"objective-c",
"ios",
"uilabel"
],
"view_count": 10,
"owner": {
"user_id": 1418175,
"display_name": "Kamran Pirwani",
"reputation": 12,
"user_type": "registered",
"profile_image": "http://www.gravatar.com/avatar/477769b38fa65ab070a14d29e61c81ef?d=identicon&r=PG",
"link": "http://stackoverflow.com/users/1418175/kamran-pirwani"
},
"link": "http://stackoverflow.com/questions/11639593/uilabel-does-not-display-all-the-text",
"is_answered": false
},
{
"question_id": 11639592,
"last_edit_date": 1343165816,
"creation_date": 1343165332,
"last_activity_date": 1343165816,
"score": 0,
"answer_count": 0,
"title": "no packages or platforms in sdk manager",
"tags": [
"android",
"eclipse",
"eclipse-adt"
],
"view_count": 13,
"owner": {
"user_id": 1549903,
"display_name": "tasneem radwan",
"reputation": 1,
"user_type": "registered",
"profile_image": "http://www.gravatar.com/avatar/97b31c0b552572afceca5f5a4b244d90?d=identicon&r=PG",
"link": "http://stackoverflow.com/users/1549903/tasneem-radwan"
},
"link": "http://stackoverflow.com/questions/11639592/no-packages-or-platforms-in-sdk-manager",
"is_answered": false
},
{
"question_id": 11639585,
"creation_date": 1343165311,
"last_activity_date": 1343165311,
"score": 0,
"answer_count": 0,
"title": "C++ /cli Marshal, String^ to std::string",
"tags": [
"string",
"c++-cli",
"marshalling",
"std"
],
"view_count": 5,
"owner": {
"user_id": 1492812,
"display_name": "user1492812",
"reputation": 39,
"user_type": "registered",
"profile_image": "http://www.gravatar.com/avatar/8c53bd1c4cfa23b278fd611c982be08c?d=identicon&r=PG",
"link": "http://stackoverflow.com/users/1492812/user1492812",
"accept_rate": 25
},
"link": "http://stackoverflow.com/questions/11639585/c-cli-marshal-string-to-stdstring",
"is_answered": false
},
…
https://api.stackexchange.com/2.1/search/advanced?order=desc&sort=creation&title=process&site=stackoverflow returns a different set of questions (none of them with “process” in the title). On the other hand, https://api.stackexchange.com/2.1/search/advanced?order=desc&sort=creation&title=algorithm&site=cs and https://api.stackexchange.com/2.1/search/advanced?order=desc&sort=creation&title=helloworld&site=cs return identical results (which from a cursory inspection seem to be the most recent questions on the site).