Data Services In Joliet IL At NW Database Services

Data Cleaning, Data Cleansing, Data Scrubbing, Deduplication, Data Transformation, NCOA, Mail PreSorts, Email Verification, Email Append, & Phone Append Services in Joliet Illinois

Get The Best Database Services In Joliet Illinois

We provide data services to businesses and organizations in Joliet IL and all Illinois cities. With over 3 decades of experience in the database business, you won’t find a company that can solve your specific database needs with higher quality service or better prices than Northwest Database Services. No matter what your specific need is, our team will find a data service solution to suit your situation.


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We Are A Full Service Data Services That Can Help You Run Your Business

Northwest Database Services is a full-spectrum data service that has been performing data migration, data scrubbing, data cleaning, and de-duping data services for databases and mailing lists, for over 34 years. NW Database Services provides data services to all businesses, organizations, and agencies in Joliet IL and surrounding communities.

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What We Do

Database Services

When you need your data to speak to you regarding your business’s trends, buying patterns or just whether or not your customers are still living.

Data Transformation

We provide data transformation services for Extract, Transform and Load (ETL) operations typically used in data migration or restoration projects.

De-duplication Service

Duplication of data plagues every database and mailing list. Duplication is inevitable, constantly keeps growing and erodes the quality of your data.

Direct Mail - Presorts

It’s true the United States Postal Service throws away approximately thirty five percent of all bulk mail every year! Why so much? Think: “Mailing list cleanup.

Email-Phone Append

With access to more than 500 million email addresses, Northwest Database Services uses one of the most comprehensive and unique data sets in the industry.


Over 40 million Americans change their address annually, which makes us do the work to maintain a high-quality mailing list while you focus on your business.

We Are Here To Help!

1 + 15 =


Woodland, WA 98674


gch [@]
To use email, remove the brackets


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(360) 841-8168

Information About Data Cleaning And Data Services

What is Hypothesis Testing?

Hypothesis testing involves confirming that your samples support your hypothesis. This is done in order to eliminate any possibility of an accidental result. The clinical trials for the covid-19 vaccine are an example of this. To ensure that the vaccine can be tested on a large number of people, we conduct many trials using a limited number of random samples.

The hypothesis test could ask the following question: “Does covid-19 cause severe illness?” We can determine whether the vaccine works by comparing data from different populations. If the results of all samples are similar and the data is both representative and random, we can conclude that the vaccine will have the same effect on everyone. It is also important to investigate why certain samples are more effective than other. There are two possibilities: the vaccine was administered to different groups or the sampling process was flawed. One of the Covid vaccines was more effective than the others in the trial due to dosing errors. This is a good example of the importance hypothesis testing. If the outlier group were just discarded, the vaccine would be much less effective.

What is a Confidence Period?

Confidence intervals, which are based on samples, can be used for estimating parameters that are relevant to measuring a population (such as the mean). The confidence interval is not a single value, but rather a range. It is often expressed in percentages. A confidence interval is used to verify that the conclusions drawn from a sample are correct.

Let’s say you have 40 randomly selected cats and their tails were measured. The average length of tails measured is 17.5 cm. The average deviation in tail length is 2 cm. A special formula can be used to calculate the average lengths of tails for all cats. This results in a 95% confidence interval. This means that 95%, which is impossible to know without measuring all of population, falls within this range. This is a great way to test the accuracy of sampling methods.

What is Regression and Correlation Analysis?

Regression and correlation analysis are both options to determine the relationships between two or more variables.

Regression analysis analyzes how one dependent variable (or output), is affected by one or several independent variables (or inputs). This can be used to test hypotheses or for predictive analytics. You could use this data to predict future sunscreen sales (an input variable) by comparing sales from the previous year with weather data (which may be both input variables), in order determine how sunny days have affected sales.

Correlation analysis is a method of determining the degree to which two or more datasets are related. Contrary to regression analysis, correlation analysis doesn’t infer cause-and effect.

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

City of Joliet IL Information

Joliet Illinois

Joliet is a city in Will and Kendall counties in the U.S. state of Illinois, 35 miles (56 km) southwest of Chicago. It is the county seat of Will County. At the 2020 census, the city was the third-largest in Illinois, with a population of 150,362.


Louis Jolliet and Father Jacques Marquette paddled up the Des Plaines River in 1673. They camped on a large earthwork mound just a few miles from present-day Joliet. Jolliet’s explorations of the area revealed a large hill or mound that was located downriver from Chicago. This is called Mont Joliet. Mining has caused the mound to be flattened.


Joliet enjoys a hot, humid continental climate. It has hot, humid summers and cold winters that receive moderate to heavy snowfall.


The city was home to 147,433 residents, 48,019 families, and 34,900 households as of 2010. The average population density was 2,288.3 people per square mile (883.5/km2). Average housing density was 796 per square mile (283.5/km2). The city’s racial composition was 67.48% White with 15.98% African American and 0.32% Native American. It averaged 796 per square mile (307.3/km2). 27.14% of the city’s population were Hispanics and Latinos.


Joliet is located about 40 miles (64km) southwest of Chicago. It has been a major transportation hub for many years. It is located on both banks of the Des Plaines River in Northern Illinois. This river is a major waterway and one of the main ports along the Illinois and Michigan Canal. In the 1850s, the Chicago & Rock Island Railroad and Michigan Central were established. The Atchison, Topeka and Santa Fe Railway and Chicago & Alton Railroad followed soon. Elgin, Joliet and Eastern Railway, as well as Milwaukee Road lines, were also built in the 20th century. The city was served by U.S. Highways 6 and 30 (the Grand Army of the Republic Highway), 45, 52, 66 (Route 66), and 66 (Route 66). Interstate 55 and Interstate 80 connected Joliet near Channahon, just west of the city’s limits, in the 1960s. Joliet’s seal contains the phrase “Crossroads of Mid-America” which refers to the intersection of I-80/I-55.

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Joliet, like many Midwestern and East Coast towns dependent on the manufacturing industry, has had economic difficulties in the past. Joliet’s unemployment rate was 8.6% in 2013. The city is changing from being a suburb of steel and manufacturing to becoming a commuter suburb within the Chicago metropolitan region. Many new immigrants to Chicago are living and working in Joliet, the nation’s second-most populous County.


Joliet IL Map