Difference Between Independent and Dependent Variables

Difference Between Independent and Dependent Variables The two main variables in an experiment are the independent and dependent variable. An independent variable is the variable that is changed or controlled in a scientific experiment to test the effects on the dependent variable. A dependent variable is the variable being tested and measured  in a scientific experiment. The dependent variable is dependent on the independent variable. As the experimenter changes the independent variable, the effect on the dependent variable is observed and recorded. Independent and Dependent Variable Example For example, a scientist wants to see if the brightness of light has any effect on a moth being attracted to the light. The brightness of the light  is controlled by the scientist. This would be the independent variable. How the moth reacts to the different light levels (distance to light source)  would be the dependent variable. How to Tell the Variables Apart The independent and dependent variables may be viewed in terms of cause and effect. If the independent variable is changed, then an effect is seen in the dependent variable. Remember, the values of both variables may change in an experiment and are recorded. The difference is that the value of the independent variable is controlled by the experimenter, while the value of the dependent variable only changes in response to the independent variable. Remembering Variables With DRYMIX When results are plotted in graphs, the convention is to use the independent variable as the x-axis and the dependent variable as the y-axis. The DRY MIX acronym can help keep the variables straight: D is the dependent variableR is the responding variableY is the axis on which the dependent or responding variable is graphed (the vertical axis) M is the manipulated variable or the one that is changed in an experimentI is the independent variableX is the axis on which the independent or manipulated variable is graphed (the horizontal axis) Independent vs Dependent Variable Key Takeaways The independent and dependent variables are the two key variables in a science experiment.The independent variable is the one the experimenter controls. The dependent variable is the variable that changes in response to the independent variable.The two variables may be related by cause and effect. If the independent variable changes, then the dependent variable is affected. Sources Carlson, Robert. A concrete introduction to real analysis. CRC Press, 2006. p.183.Dodge, Y. (2003) The Oxford Dictionary of Statistical Terms, OUP. ISBN 0-19-920613-9Everitt, B. S. (2002). The Cambridge Dictionary of Statistics (2nd ed.). Cambridge UP. ISBN 0-521-81099-X.

Dromiceiomimus - Facts and Figures

Dromiceiomimus - Facts and Figures Name: Dromiceiomimus (Greek for emu mimic); pronounced DROE-mih-SAY-oh-MIME-us Habitat: Plains of North America Historical Period: Late Cretaceous (80-65 million years ago) Size and Weight: About 12 feet long and 200 pounds Diet: Probably omnivorous Distinguishing Characteristics: Relatively large eyes and brain; long legs; bipedal posture About Dromiceiomimus A close relative of the North American ornithomimids (bird mimic dinosaurs) Ornithomimus and Struthiomimus, the late Cretaceous Dromiceiomimus may have been the fastest of the bunch, at least according to one analysis of this theropods unusually long legs. At full tilt, Dromiceiomimus may have been capable of hitting speeds of 45 or 50 miles per hour, though it probably stepped on the gas pedal only when it was being pursued by predators or itself in pursuit of small, skittering prey. Dromiceiomimus was also notable for its relatively large eyes (and correspondingly big brain), which matched up oddly with this dinosaurs weak, toothless jaws. As with most ornithomimids, paleontologists speculate that Dromiceiomimus was omnivorous, feeding mostly on insects and vegetation but pouncing on the occasional small lizard or mammal when the opportunity presented itself. Now for the catch: many, if not most, paleontologists believe that Dromiceiomimus was actually a species of Ornithomimus, and not deserving of genus status. When this dinosaur was discovered, in Canadas Alberta province in the early 1920s, it was initially classified as a species of Struthiomimus, until Dale Russell reexamined the remains in the early 1970s and erected the genus Dromiceiomimus (emu mimic). A few years later, though, Russell changed his mind and synonymized Dromiceiomimus with Ornithomimus, arguing that the main feature distinguishing these two genera (the length of their legs) wasnt truly diagnostic. Long story short: while Dromiceiomimus persists in the dinosaur bestiary, this difficult-to-spell dinosaur may soon go the way of Brontosaurus!