Hi, I was reading a definition of "experiment" in science to be used in a lecture and the use of treatments and controls are an important feature of an experiment but.... my doubt is... is it possible to plan an experiment without a control and call this as an "experiment" ?
For example, in a polluted river basin there is a gradient of contamination and someone are interested in to compare the fish diversity in ten rivers of this basin. Then, the "pollution level" are the treatment (with ten levels) but if there is not a clean river in the basin, I cannot use a control ! Is this an experiment anyway ? Thanks for any comments..... Voltolini _____________________________________________ Prof. J. C. VOLTOLINI Grupo de Estudos em Ecologia de Mamiferos - ECOMAM Universidade de Taubate (UNITAU) Departamento de Biologia Taubate, SP, Brasil. CEP 12030-010 Tel: 0XX12-2254165 (lab.), 2254277 (secret. depto.) FAX: 12 - 2322947 E-Mail: [EMAIL PROTECTED] _____________________________________________ ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at http://jse.stat.ncsu.edu/ =================================================================