A strain of E. coli SC18del-recA718 is placed into a nutrient broth at 30 Celsius and allowed to grow. The data below are collected. Theory states that the number of bacteria in the petri dish will initially grow according to the law of uninhibited growth. The population is measured using an optical device in which the amount of light that passes through the petri dish is measured. Time (hours), x Population, y 2.5 3.5 4.5 4.75 5.25 0.175 0.38 0.63 0.76 1.20 Source: Dr. Polly Lavery, Joliet Junior College (a) Draw a scatter diagram treating time as the independent variable. (b) Using a graphing utility, build an exponential model from the data. (c) Express the function found in part (b) in the form N(t) = N0 ekt. (d) Graph the exponential function found in part (b) or (c) on the scatter diagram. (e) Use the exponential function from part (b) or (c) to predict the population at x = 6 hours. (f) Use the exponential function from part (b) or (c) to predict when the population will reach 2.1.
Media Effects (Chapter 15) Media effects is the field of research that attempts to understand, predict, and explain the effects of mass media on individuals and society o scientific method: understand, predict, and explain o individuals and society: media does not only effect the individual but society as well Not all media researchers are studying "effects" or aiming for prediction o Cultural studies researchers try to understand how media constructs and is constructed by questions of gender, race, social class, nationality, etc. o Rhetorical studies researchers try to understand how media functions in terms of persuasion, meaning, political contestation, ideology, identity, etc. Media Effects Theories The Hypodermic Needle Model o An early model for television effects on audiences o The idea that powerful media shoot their messages directly into vulnerable audiences' brains o Also known as the "magic bullet" or "direct effects" model o Fails to account for the fact that people are critical and skeptical of media messages o Widely discredited by subsequent research The Minimal Effects Model o Media effects are less powerful, and are mostly indirect. o Also known as the "limited model" o People engage in selective exposure: We tend to expose ourselves only to messages that we are already comfortable with o People engage in selective retention: We tend to retain messages that confirm the values and ideas that we already hold o This model still assumes that audiences are passive in their consumption of media Uses and Gratifications o Studies how and why media are used, rather than what their effects are o The surveillance function suggests that people use the media to monitor the world around them o Similarly, the socialization function suggests that people use the media to help fit in with others o While the textbook says this model was never widely adopted, it has been incorporated into rhetorical and cultural studies research. What Effect Does the Media Have The most significant demonstrated effect of media is agenda- setting: o Not telling people what to think, but telling them what to think about Many of the other effects listed in the textbook are less well proven but still worth discussing The cultivation effect is the idea that heavy TV viewing causes is to believe that TVis giving us an accurate portrayal of the real world o One common version of this is the mean world syndrome: we believe the world is more dangerous than it really is because TV shows so much crime The spiral of silence theory is the idea that the media silences controversial opinions by making those who have them fear social invasion o This can even be true of opinions that are not really controversial, since the media edits out very widely held opinions o Some studies indicate that we are even willing to go along with wrong answers if "everyone else" is giving those answers too