John Dyer

While working with some book data, I needed to merge the old ISBN-10 and ISBN-13 data. Unfortunately, I couldn't find any C# code to do the conversion. Search for "ISBN C#" in Google only return book stores with C# books.

So here is a little class that will convert and validate ISBNs. Here's how the code would look:

string isbn10 = "0830818030"; 
string isbn13 = ISBN.Convert10to13(isbn10); // returns "9780830818037"

string isbn = "083081803X"; // this one has a bad checksum (last digit) 
string correctIsbn = ""; 
if (!ISBN.IsValid(isbn, out correctIsbn)) { 
	isbn = corretnIsbn; // returns "0830818030"
}

An ISBN object can also be instantiated and used:

IBSN myBook = new ISBN("0-83081-803-0"); 
string isbn13 = myBook.ISBN13; // returns "9780830818037"
string isbn10 = myBook.ISBN10; // returns "0830818030" 

Here is the class:

public class ISBN
    {

        public ISBN(string isbn)
        {
            SetIsbn(isbn);
        }

        private string _isbn10 = "";
        private string _isbn13 = "";

        public string ISBN10
        {
            get
            {
                return _isbn10;
            }
            set
            {                
                string corrected = "";
               
                if (!IsValid(value, out corrected) && corrected == "")
                    throw new Exception("invalid ISBN");

                SetIsbn(corrected);
            }
        }

        public string ISBN13
        {
            get
            {
                return _isbn13;
            }
            set
            {
                string corrected = "";

                if (!IsValid(value, out corrected) && corrected == "")
                    throw new Exception("invalid ISBN");

                SetIsbn(corrected);
            }
        }

        private void SetIsbn(string isbn)
        {
            isbn = CleanIsbn(isbn);

            if (isbn.Length == 10)
            {
                _isbn10 = isbn;
                _isbn13 = Convert10to13(isbn);
            }
            else if (isbn.Length == 13)
            {
                _isbn13 = isbn;
                _isbn10 = Convert13to10(isbn);
            }
        }

        private static string CleanIsbn(string isbn)
        {
            return isbn.Replace("-", "").Replace(" ", "");
        }


        public static string Convert10to13(string isbn)
        {
            return Convert10to13(isbn, true);
        }
        public static string Convert10to13(string isbn, bool throwError) {
            
            // remove - and space
            string isbn10 = CleanIsbn(isbn);

            if (isbn10.Length != 10 && throwError)
                throw new Exception("ISBN must be 10 characters long");

            // 1) Drop the check digit (the last digit)
            isbn10 = isbn10.Substring(0, 9);

            // 2) Add the prefix '978' 
            string isbn13 = "978" + isbn10;

            // 3) Recalculate check digit 
            isbn13 = isbn13 + Isbn13Checksum(isbn13);

            return isbn13;
        }

        public static string Convert13to10(string isbn)
        {
            return Convert13to10(isbn, true);
        }

        public static string Convert13to10(string isbn, bool throwError)
        {

            // remove - and space
            string isbn13 = CleanIsbn(isbn);

            if (isbn13.Length != 13 && throwError)
                throw new Exception("ISBN must be 13 characters long");

            // 1) Drop the check digit (the last digit) and prefix '978'
            string isbn10 = isbn13.Substring(3, 9);
     
            // 2) Recalculate your check digit using the modules 10 check digit routine.
            isbn10 = isbn10 + Isbn10Checksum(isbn10);

            return isbn10;
        }

        public static bool IsValid(string isbn)
        {
            string correctIsbn = "";
            return IsValid(isbn, out correctIsbn);
        }

        public static bool IsValid(string isbn, out string correctISBN)
        {
            // remove - and space
            isbn = CleanIsbn(isbn);

            if (isbn.Length == 10) {
                return ValidateIsbn10(isbn, out correctISBN);
            }
            else if (isbn.Length == 13)
            {
                return ValidateIsbn13(isbn, out correctISBN);
            }
            else
            {
                correctISBN = "";
                return false;
            }

        }

        private static string Isbn10Checksum(string isbn)
        {
            int sum = 0;
            for (int i = 0; i < 9; i++)
                 sum += (10-i) * Int32.Parse(isbn[i].ToString());
   
            float div = sum / 11;
            float rem = sum % 11;

            if (rem == 0)
                return "0";
            else if (rem == 1)
                return "X";
            else
                return (11 - rem).ToString();
        }

        private static string Isbn13Checksum(string isbn)
        {
            float sum = 0;
            for (int i = 0; i < 12; i++)
                sum += ((i % 2 == 0) ? 1 : 3) * Int32.Parse(isbn[i].ToString());

            float div = sum / 10;
            float rem = sum % 10;

            if (rem == 0)
                return "0";
            else
                return (10 - rem).ToString();
        }


        private static bool ValidateIsbn10(string isbn, out string correctISBN)
        {
            correctISBN = isbn.Substring(0, 9) + Isbn10Checksum(isbn);

            return (correctISBN == isbn);
        }

        private static bool ValidateIsbn13(string isbn, out string correctISBN)
        {
            correctISBN = isbn.Substring(0, 12) + Isbn13Checksum(isbn);

            return (correctISBN == isbn);
        }
}

I initially wanted to also make a method that would add back in the correct dashes, but I found out that the make up is based on country and publisher codes assigned by the International ISBN Agency which regularly updates the list of codes making it pretty much impossible to permanantly functionalize.

For the last few years, my web team has used a projector to collaborate on web projects. We use it for going through our weekly work items, demoing designs, doing training, and so on.

Unfortunately, it was an old projector with a weak bulb so we always had to turn out the lights to use it. Even then it was hard to see because the contrast and color depth were poor, and the resolution was only 1024x768. So last year I budgeted to get a new projector to solve these problems.

Instead of getting a new projector, I decided to get a LCD HDTV and use it as a monitor. I found a killer deal at Sam's Club on a 65" Olevia. The screen isn't quote as nice as something like a Sony, but for what we are doing, it is absolutely amazing. The 1920x1080 resolution and super bright LCD screen is perfect for looking at web designs. In this pic, We have our task app on the right and a full size web page on the left. Even though the text is tiny it's readable from about 8' away:

I have an old PC running the display, and I'm using a few little utilities to make enhance presentations:

• PowerStrip - Some PCs and Macs can't natively display 1920x1080 resolution. This little Windows app helps out and can usually enable even really old machines to do HD resolutions.
• ZoomIt - this is a little app by the former SysInternals.com guys. It lets you zoom into a screen with the mouse scroll wheel and draw on the screen. This features are invaluable for mockups.
• Zune Theme Modified - I also used a modified Zune theme, because I like how the dark colors make the UI fade into the background and focus attention on the design.

On the fun side, we can occasionally use it for things other than web design. Since we're in a basement, we don't have a good way of getting an antenna to pipe in some HD goodness, but we can watch trailers in full 1080p goodness!

Note: This blog is usually fairly technical, dealing with ASP.NET, Flash, and JavaScript code samples, but this is a brief deviation into the broader world of the web as a technology platform for communicating an institution's message.

For Dallas Theological Seminary, we've been experimenting with "branding" and reaching different audiences by producing some new videos and experimenting with Facebook's relatively new targeted advertising.

Marketing for Seminaries?

Advertising and marketing for churches and seminaries can be a tricky thing, because it seems rather sacrilegious to "market" something spiritual. We've all seen late night and afternoon televangelists that make us cringe. But DTS isn't offering a "product" that someone buys; rather its mission is to train pastors, professors, and missionaries for a lifetime of service. If you call an admissions counselor and ask why you should go to DTS, you won't get a sales pitch. The admissions counselor will tell you that you should go to the school to which God is calling you. The admissions person will then mention some of DTS's strengths, but stay away from comparisons with other schools or "selling DTS."

Still, it is important for DTS to inform prospective students on what kind of school it is and what it's strengths are. Basic marketing ideas can help convey this, and naturally the web is a great place to start.

Context for the Advertisements

Any time you create an ad for a "company," it is important to know the background of the business and the historical context in which the ad is situated. This history of seminaries and churches in America is key to understanding what ads will communicate to the seminary audience.  

In the early 1900s, was a debate in the Christian church between "fundamentalists" (those who believe certain truths are the most important thing about Christianity) and "liberals" (those who believe certain actions are the most important thing about Christianity). In this debate, it seemed that the "liberals" forgot that Jesus asked Christians to believe something (that he is the savior and the Son of God), while the the fundamentalists often forgot that Jesus asked Christians to do something (love others).

DTS was started in the 1920s during the fundamentalist movement. Unfortunately, many of the seminaries which started during this time period have a reputation of caring about teaching the Bible, but neglecting to meet real world needs. By the 60s and 70s, some Christians wanted to balance the emphases of both the liberals (loving) and fundamentalists (truth), and there they were called "evangelicals." Today, this term has become politically decisive and has less positive connotations in many places, so the word "evangelical" communicates something different than it used it.

Today's students who are considering seminary are more concerned than ever about balancing these two things and so DTS needs new ways to communicate that it wants to care about Christian beliefs and Christian practices without making one too dominate. These students also don't read traditional Christian publications, so DTS needs to shift from print publications to Internet and from top down communication to allowing prospects to connect to real students.

A New Tagline

The older taglines for DTS have been things that primarily emphasize Biblical teaching such as "Standing Strong for the Truth" or "Training You Can Trust. Leaders You Can Follow."

We wanted something shorter and somewhat pithy that emphasized both aspects of truth and love. Here's what we came up with.

• Teach Truth. Love Well.

Not too revolutionary, but hopefully it's clear and it communicates. Here's how Google sees it :)

Facebook Page and Ads Summary

DTS has traditionally run ads on large Christian website like ChristianityToday.com and OnePlace.com. But to reach younger students, we moved over to Facebook.

Also, in the past, a traditional DTS ad might have emphasized something like "Want to be a Pastor?", but many of today's seminarians are going into non-traditional forms of ministry. DTS grads still have a very strong emphasis on teaching the Bible, but more students are doing this outside the traditional church pastor role. The first few ads we ran emphasize these other forms of ministry. We ran each one for around a week and paid per click with click-through rates of around 0.10%.

Which one do you like more?

The second ad turned out to be more successful (higher click-through rates). This is probably because the image is more appealing and "Dallas Seminary" doesn't show up until later in the text of the ad.

In addition to advertisements, we also setup a Facebook Page for DTS. Rather than aggressively market to students through physical mail or email blasts, this allows interested students to check out DTS and ask questions of current students and alumni before talking to an admissions counselor. On the GoingToSeminary blog, there is a great post about connecting to a current student to get real answers. Below is an example of a prospect asking a question that a current student answered on Facebook. That person got a real answer from a real student without ever needing to visit the main seminary website.

Connecting with Video

DTS's excellent AV team has also produced several videos that communicate the "Teach truth. Love Well." message. These are sent to alumni and supporters via email every few months.

Ben Stuart
Ben leads a college ministry called BreakAway which is attended by about 5,000 Texas A&M (my alma mater) students. His story is classic DTS and emphasizes "Teach Truth".

Christ in North Africa
Where Ben highlights "Teach Truth," Christy highlights "Love Well." She is an English teacher North Africa, but never "teaches" Christianity verbally; she does it by loving the girls in her classes.

William "Duce" Branch
"Duce" Branch is a pastor who ministers to the hip hop generation through his music.This is a guy who took 120 hours of course work and still managed to keep his love for his culture. He really embraces both elements of "Teach Truth. Love Well."

This last video also has a great metaphor for communicating to different audiences where the president of the school is shown on an upper-middle-class HDTV while Duce is shown on various older TVs. They both are working for the same goal with the same message, but the context and transmission system changes to be audience appropriate. Good stuff.

I hope this is a helpful summary of how DTS works and how the newer media forms can be used to communicate to changing audiences.