Data Services In Knoxville TN At NW Database Services

Information About Data Cleaning

There Are Two Types Of Outliers

• Univariate outliers are extreme values that only relate to one variable. Sultan Kosen, who stands 8 feet, 2.8 inches (251 cm) tall, is the current tallest man in the world. This case is a rare univariate exception because it has one factor, height.
• Multivariate outliers are combinations of extreme or unusual values for at most two variables. If you look at the height and weight of an adult group, you may notice that one person is 5ft 9ins tall. This measurement would be within the normal range of this variable. This person might also be 110 lbs. This observation is within the normal range of the variable of interest, weight. These two observations are combined to create an adult who stands 5ft 9inches tall and is 110lbs. This is a remarkable combination. This is a multivariate outlier.

Outliers can be classified as any one of the following:

• Global outliers, also known as point outliers, are data points that lie far from the rest.
• Contextual outliers, also known as conditional or outliers, are values that significantly differ from the rest of data points in the same context. This means that a value that occurred in a different context may not be considered outlier. This category is often found in time series data.
• Collective outliers can be described as a subset or group of data points that is completely different from the whole dataset.
  We now know what an outlier looks like, so let’s see how they end up in data sets.

How Can Outliers Get Into Datasets?

After we have learned what outliers look like and how to identify them it is worth asking how they end up in data sets in the first place.
Here are some common reasons for outliers in data:

• Human error when manually entering data, such a typo
• Intentional errors such as dummy-outliers in a dataset used to test detection methods
• Sampling errors are caused by the extraction or mixing of data from incorrect or multiple sources
• Data processing errors can result from data manipulation or unintended modifications to a dataset.
• Instrumental error can cause measurement errors
• Experiment planning and execution errors can result from data extraction or experiment planning.
• Natural outliers are those that occur naturally in the data, and not because of any error. These errors are called novelties.

How Do You Spot Outliers?

It is possible to spot outliers in small datasets. For example, if you have 28 26, 21, 24, and 78 data sets, you can see that the outlier is 78. However, when dealing with large datasets or big-data, additional tools are needed.

Northwest Database Services has 34+ years experience with all types of data services, including mail presorts, NCOA, and data deduplication. If your database systems are not returning poor data, it is definitely time for you to consult with a data services specialist. We have experience with large and small data sets. Often, data requires extensive manipulation to remove corrupt data and restore the database to proper functionality. Call us at (360)841-8168 for a consultation and get the process of data cleaning started as soon as possible.

NW Database Services
404 Insel Rd
Woodland WA 98674
(360)841-8168

Knoxville is the city and county seat in Knox County, Tennessee. Knoxville had a population of 190,740 at the 2020 United States Census. This makes it the third-largest city in East Tennessee Grand Division, and the third-largest city in Tennessee after Nashville and Memphis. Knoxville is the capital city of Knoxville Metropolitan Statistical Area. It had an estimated population 869,046 as of 2019.

History

Knoxville, Tennessee’s first capital, was established in 1786. Throughout the 19th century, Knoxville struggled with its geographic isolation. Economic boom was brought about by the arrival of the railroad in 1855. The secession issue in the American Civil War caused bitter division in the city. It was occupied alternately between Union and Confederate armies. This culminated in the Battle of Fort Sanders, 1863.

Climate

Knoxville is located in the subtropical humid climate. The summers are hot and humid with the average daily temperature of 78.4 degrees F (25.8 degrees Celsius) and an average of 36 days with temperatures as high as 90 degrees (32 degC) on average. Winters are usually much cooler and more stable with occasional snow. January’s average daily temperature is 38.2 degrees F (3.4 degrees Celsius), but most years there are at least one day (average of 5.3) when the high remains below freezing.

Demographics

The population of Knoxville, at 178,874, was 2.9% higher than 2000. The median age was 32.7 with 19.1% under 18 and 12.6% above 65. 48% of the population were male, 52% were female. The population density was 1,815 people per square mile.

Transportation

Two major interstate highways serve Knoxville: Interstate 40 (directly), which connects to Asheville and Bristol (via I-81) (to the east and Nashville (to the west), and Interstate 75 (which connects the city with Chattanooga and Lexington to both the south and north).

Top Businesses

Knoxville was a major manufacturing and wholesaling center after the 1850s arrival of railroads. Knoxville’s economy became more diverse after the demise of its textile industry in 1950. 15.9% of Knoxville Metropolitan Statistical Area’s 2011 work force were employed by government agencies. 14% were in education and health care, 14% were in professional services, 14% were in education and health care, 12.7% in retail, 10.5% in leisure and hospitality, 8.9% were in the manufacturing sector. In 2011, the region’s unemployment rate was 7.9%.

Knoxville TN Map