business notes: more on spreadsheets and websites
TRANSCRIPT
Business Notes:More on Spreadsheets and Websites
ITGS - Spreadsheets
All spreadsheets are based around the fundamental concepts of •cells of data
• Each cell can contain data or a formula• Each cell has a cell type – controls how data is presented.
• examples: numeric, data, text, or scientific•cell references – references to these cells
Each cell has an individual cell reference, such as A1 or C3, which refers to its contents.
ITGS – Spreadsheet Formulae
• Formulas• Individual cell references are used to build up formulas to perform
calculations• Cell ranges – a sequence of cells, such as A1:A4 (this refers to cells A1, A2,
A3, and A4• Automatic recalculation – a function that means when a value in a cell
changes, the results produced by any formulae depending on that cell will be updated.
Each cell has an individual cell reference, such as A1 or C3, which refers to its contents.
ITGS – Absolute & Relative Cell Referencing
• Absolute and Relative Cell Referencing• relative cell reference - A cell reference that
updates itself when moved• When D1 below is moved to the next row, it will
change to B3*C3
Absolute cell reference – when the formula needs to always refer to one specific cell, a dollar sign is used to indicate ‘never change this cell reference’.
ITGS – FunctionsFunction – •A built-in option to perform a common operation.
• Common functions:• Maths functions
• Includes rounding numbers, calculating powers or factorials, and calculating averages.Also can find absolute values, square roots, trigonometry fucntions, calculate standard deviation and perform data conversion between decimal, octal, binary and hexidecimal.
• Text functions• Can convert between both numeric and text value, change from
uppercase to lowercase or vice-versa, and remove extra spaces from text cells
• Logic functions• Produces results based on the status of other parts of the
spreadsheet• Count, min, and max
• Date functions• Time and date functions; can figure out data like number of
days
ITGS – FunctionsAdditional features• Conditional formatting – can change the formatting of a cell depending on its content
• For example: cells with negative values can appear red, and cells with percentages over 80 can be green
•Cell locking – if some cells need to not be changeable•Pivot table – an advanced output feature which can provide a summary of data in a spreadsheet
ITGS – Web DesignThe design, accessibility and usability of an e-commerce web site are critical factors in achieving a high conversion rate
• Conversion rate • The percentage of visitors who eventually decide to make purchases• Research states that if consumers can’t find what they want in 4
seconds, they leave the site•Basic web pages are written in HTML
• HTML (HyperText Markup Language)• Each page on a web site is saved as a separate file with an .html
or .htm extension• HTML tags start and end with angled brackets and control how a web
page appears• Basic web pages can be written using HTML in a text editor, but most
designers prefer to use a WYSIWYG (what you see is what you get) web site design package • It is easier to use these because of the graphical tools that
automatically generate HTML code without the creator having to know them
• You can still manually alter the code if you know HTML
ITGS – Web Design
A problem with HTML is that it contains both data and page styling information in code for each part of each page, and it takes forever to make frequent or wide-spread changes
A solution to many of these problems is to use CSS (Cascading Style Sheets)• CSS allows you to format styles for parts of the page and repeat them by choosing that style throughout the web site
• CSS div tags divide the page content (in HTML, denoted by the <body> tags) into sections, assigning styles to each one
• Hyperlinks use the <a href> tag• External links – link to pages in other websites• Internal links, or anchors, link to content on the current page• Relative links – specify the name of the linked page without its full URL.
The browser assumes the page is on the current site.
ITGS – Web Design
Data-driven web sites•Pages whose content is fetched from a database using a query which is run when the page is requested (such as an online shopping site)
• Data is stored in a back-end database such as a SQL server, MySQL, or Oracle
• A programming language such as ASP (Active Server Pages) , ASP.NET or PHP (Hypertext Preprocessor) is used on the web server to extract the required data from the database and build an HTML web page, which is sent to the user for viewing by the web browser
ITGS – Web Design
Interactive web sites•Scripting languages like JavaScript can be used to enhance web pages and make them more interactive and dynamic•Multimedia plugins like Adobe Flash and Microsoft Silverlight can add even more functionality, and are often used for games, animations, embedded video, interactive quizzes, and other multimedia applications.
Downsides to using Multimedia plugins• Java – a programming language used to create applets that run inside
web pages• Java applets – normal programs that obey a series of security
restrictions to make them safer for internet use• Browser plugins must be installed in browsers before Flash,
Silverlight or Java can be used• Flash cannot be used on Apple iPhone and iPad
• The use of multimedia can increase bandwidth and page load time• Some search engines consider loading speed when ranking pages in
their results
ITGS – Web Design
Web page compatibility•Older browsers often don’t support the technology used in interactive web sites, so developers should provide alternate versions of the page for them.
Web site features•Breadcrumb trail – a navigation map that shows the user exactly where they are and how they got there:
• i.e.: Home>Equipment>Lenses>Wide Angle
Web standards•The World Wide Web Consortium (W3C) is the organization responsible for developing standards for the web.
• Standards include:• HTML – the standard language for web pages• CSS – a standard for formatting web pages
ITGS – Web Design
Cookies• Small text files stored in a special folder on your hard disk by some of the
web sites you visit.• The cookies are used to store small amounts of data about you
• How do cookies work?• The site makes a cookie with a unique identification number (UID)• When you revisit the site, the UID indicates that you are a returning
visitor• The UID can be used to look up your data in a database held by the
web site
Designing for Accessiblity• alt attribute:
• Attaching words to the rollover of an image on a website; this is nice to do for handicapped people
ITGS – Web Design
WebCMS•Web Content Management Systems
• Allows a user with minimal knowledge of HTML or CSS to post information in software similar to a word processor• Examples are Blackboard or Moodle
Publishing a Web Site•Sites have to be uploaded to a web host•You must have a domain name•Upload the site using a File Transfer Protocol (FTP) server