How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Martin Your Own Question

Martin
Martin, Physicist
Category: Pre-Calculus
Satisfied Customers: 765
Experience:  20+ years of research, engineering and teaching
47181708
Type Your Pre-Calculus Question Here...
Martin is online now
A new question is answered every 9 seconds

Explain the concept of modeling. How does a model describe

Resolved Question:

Explain the concept of modeling. How does a model describe known data and predict future data? How do models break down? Can you think of an example?
Submitted: 2 years ago.
Category: Pre-Calculus
Expert:  Martin replied 2 years ago.
Hello. I'll be right back with your answer...
Customer: replied 2 years ago.
ok
Expert:  Martin replied 2 years ago.

The concept of modeling is the use of mathematics to predict the behavior of a system. It can be as simple as finding the trend in car prices, or as complex as modeling the climate of the Earth. In all cases, we describe the system by mathematical equations. The equation can be based on underlying physical principles, like gravity or electromagnetism, or they can be empirical models derived by fitting them to a set of observations. For example, we might measure the temperature at noon everyday. If we start in March, we might notice that after a month or so there is a gradual warming. We could fit a straight line to these data, and then we could predict the average temperature in June. This might work quite well, but the model wouldn’t be realistic for long-term prediction, since it would predict the temperatures keep rising. Come October, the temperatures will have stopped rising and begun cooling, and we would find our linear model isn’t adequate. After a year, we’d notice a cyclical pattern, and could then possibly fit a oscillatory function to the year-long temperatures, and come up with a good model.

The reason our initial linear model failed (in our hypothetical story) is because it extrapolated into uncharted territory. This is always a risky proposition. In general, when using empirical models like our temperature model, it’s a bad idea to extrapolate too far beyond the end of the observed data. Other ways that empirical models can break down is by spurious data. For example, suppose the thermometer was bumped or otherwise changed during the measurements, making the last few measurements colder than the actual temperature. This would skew the best-fit line, and our model would under-predict the future temperatures.

Martin, Physicist
Category: Pre-Calculus
Satisfied Customers: 765
Experience: 20+ years of research, engineering and teaching
Martin and other Pre-Calculus Specialists are ready to help you
Expert:  Martin replied 2 years ago.
Just following up. It was a pleasure working with you. Please don't hesitate to let me know if you ever have additional questions. Just put "For Martin" at the beginning of your question, and I'll be sure to get it.

Thanks,

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
< Last | Next >
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
  • He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here. Diane Dallas, TX
 
 
 

Meet The Experts:

 
 
 
  • Mr. Gregory White

    Master's Degree

    Satisfied Customers:

    153
    M.A., M.S. Education / Educational Administration
< Last | Next >
  • http://ww2.justanswer.com/uploads/ED/educatortech/2012-6-7_1256_williams4.64x64.jpg Mr. Gregory White's Avatar

    Mr. Gregory White

    Master's Degree

    Satisfied Customers:

    153
    M.A., M.S. Education / Educational Administration
  • http://ww2.justanswer.com/uploads/CO/CosumelEyes/2012-5-4_4923_Profile.64x64.jpg Ray Atkinson's Avatar

    Ray Atkinson

    Bachelor's Degree

    Satisfied Customers:

    38
    Inner-city high school substitute teacher. Degrees in mathemetics, accounting, and education. Years and years of tutoring.
  • http://ww2.justanswer.com/uploads/mhasan420/2010-1-23_19189_topi.jpg mhasan420's Avatar

    mhasan420

    Master's Degree

    Satisfied Customers:

    37
    BA Maths, Oxford
  • http://ww2.justanswer.com/uploads/SO/sonofGauss/2012-6-6_20151_PortraitLHW.64x64.jpg JACUSTOMER-yrynbdjl-'s Avatar

    JACUSTOMER-yrynbdjl-

    Master's Degree

    Satisfied Customers:

    13
    I have taught college Mathematics for the past 10 years.
  • http://ww2.justanswer.com/uploads/ME/mesosphereman/2013-2-28_12025_EarthfromApollo17small.64x64.jpg Martin's Avatar

    Martin

    Physicist

    Satisfied Customers:

    44
    20+ years of research, engineering and teaching
  • http://ww2.justanswer.com/uploads/MA/manas11/JA.64x64.JPG manas11's Avatar

    manas11

    Bachelor's Degree

    Satisfied Customers:

    12
    Tutor & Engineer
  • /img/opt/shirt.png Math-John's Avatar

    Math-John

    PhD in Statistics

    Satisfied Customers:

    211
    MS and BS in Math.
 
 
 
Chat Now With A Tutor
Martin
Martin
44 Satisfied Customers
20+ years of research, engineering and teaching