From the introduction to my hopefully soon-to-be-published translation of the work:
The text before us, authored by the great 10th century (hijrī) ḥadīth master ʿAbd al-Ḥaqq ibn Sayf al-Dīn al-Dihlawī, was composed to serve as a prolegomena to Walī al-Dīn Muḥammad ibn ʿAbdullāh al-Khaṭīb al-Tabrīzī’s monumental collection of ḥadīth entitled Mishkāt al-Maṣābīḥ. Concise yet refreshingly lucid, Dihlawī authored the treatise to assist novices in ḥadīth studies during their highly technical lectures on the Mishkāt, at that time the most advanced textbook of ḥadīth studies in the Indian subcontinent.
Because it was not intended to encompass all the sciences of ḥadīth study, the text reads more as a glossary of ḥadīth-related terms and concepts than an in-depth analysis of the sciences of muṣtalaḥ (terminology), ʿilal (subtle ḥadīth defects), and jarḥ wa taʿdīl (narrator criticism). Dihlawī’s focus, therefore, is less on the history of ḥadīth studies and its most recognized personalities and more on the commonly-used terms scholars expected students to know in order to properly benefit from ḥadīth commentary and lectures. Of the ten chapters that comprise the book, therefore, only the last two deal with the various collections of ḥadīth and their comparative status.
Original Arabic text:
at-Tahawi 
salam, where could i purchase it from?
Date: Tue, 16 Oct 2012 16:06:14 +0000
To: einadat@hotmail.com
Are you speaking about the Arabic book?
Jazakumullah khairankasiro ala khidmatikum
________________________________
When will the English translation be released?
Mawlana, Is your translation to be published in print form or electronically (online)? Jazakallah wa waffaqakallah.
I had spoken to a publisher some time ago, but since then decided to add a detailed study of the Indian scholars’ contribution to hadith literature in the introduction. This has taken a lot longer than I thought and so I don’t expect for the publisher to be still interested. I am open to all options.
Mawlana,
I have emailed you.
A translation of the work is here for those interested:
http://islamclass.wordpress.com/2012/04/20/abd-al-hayy-al-laknawis-introduction-to-ulum-al-hadith/
Al-salam ‘alaykum,
I believe that this translation was done by Mawlana Irfan Kabeeruddin many years ago. It was my dissatisfaction with the precision of this translation that prompted me to start my own, but I benefitted from his translation in many places. May Allah reward him for his work and allow him to continue with such projects. Amin.
Do you have the translation of the book now brother?