The Centre for Research into Ecological and Environmental Modelling (CREEM) is delivering an online workshop 'introduction to distance sampling' via live web conference. This workshop, in 10 meetings over two weeks, address the fundamentals of distance sampling.  We introduce the concept of a detection function, understand how to estimate probability of detection when detectability is imperfect.  The fundamental principles of this method also known as conventional distance sampling, forms the foundation upon which more advanced methods are based.