Qiyas vs. Ijtihad

Difference Between Qiyas and Ijtihad
Qiyasnoun
(Islam) The use of analogy as precedent in Shari'a jurisprudence.
Ijtihadnoun
(Islam) The process of Muslim jurists making a legal decision by independent interpretation of the Qur'an and the Sunna.
Ijtihadnoun
the endeavor of a Moslem scholar to derive a rule of divine law from the Koran and Hadith without relying on the views of other scholars; by the end of the 10th century theologians decided that debate on such matters would be closed and Muslim theology and law were frozen;
some reform-minded Islamic scholars believe that reopening itjihad is a prerequisite for the survival of Islam