Doctor of Science (Latin: Scientiae Doctor), usually abbreviated Sc.D., D.Sc., S.D., D.S., or Dr.Sc., is an academic research degree awarded in a number of countries throughout the world. In some countries, "Doctor of Science" is the title used for the standard doctorate in the sciences; elsewhere the Sc.D. is a "higher doctorate" awarded in recognition of a substantial and sustained contribution to scientific knowledge beyond that required for a PhD. It may also be awarded as an honorary degree.
In Algeria, Morocco, Libya and Tunisia, all universities accredited by the state award a "Doctorate" in all fields of science and humanities, equivalent to a PhD in the United States or the UK.
Some universities in these four Arab countries award a "Doctorate of the State" in some fields of study and science. A "Doctorate of the State" is slightly higher in esteem than a regular doctorate, and is awarded after performing additional in-depth post-doctorate research or achievement.
In these countries usually Sc.D./D.Sc. is equivalent to a United States Ph.D. in science and obtained in Graduate School after satisfactory evaluation of knowledge, research accomplishment, and the defense.
Higher education institutes in Thailand generally grant Ph.D. for research doctoral degree, except some universities such as Chulalongkorn University award D.Sc. In exception, Mahidol University can grant both Ph.D. and D.Sc. Doctoral students in Faculty of Science are always awarded Ph.D., but some other programs award D.Sc.
The higher education institutes in Uzbekistan also grant D.Sc. degrees. As an example, the National University of Uzbekistan and the Uzbekistan Academy of Sciences offer D.Sc. in various fields.
In Germany, Austria, and the German-speaking part of Switzerland, the most common doctoral degrees in Natural Sciences are the following: