UPDATED

[Update (5:30): In a conference call with investors and analysts today, K12 Inc.’s executive chairman, Nate Davis, said the company took “full responsibility” for not reaching its student-enrollment goals. The company projected operating losses in the first quarter of fiscal 2014 of between $8 million and $10 million. See more details from the call at the end of this post.]

The stock of online provider K12 Inc. took a steep plunge this week following its release of information showing more modest projections for revenue and student enrollment than analysts had anticipated.

In a statement released this week, the company estimated its average enrollment for the schools it manages at 128,000 students for the quarter, which was up nearly 6 percent from the first quarter of the previous year, yet “below management’s expectations.”

The Herndon, Va.-based company also said it expected revenues for the full fiscal year to range from $905 million to $925 million, and its operating income to fall between $53 million to $57 million, numbers that disappointed analysts. 

The measure of Wall Street’s dim view of K12’s recent showing was reflected in the company’s stock price, which plummeted from more than $29 a share to about $19 a share in the day following the release of its numbers. As of mid-afternoon today, the price was hovering above $18. (K12’s stock took a comparable plunge in late 2011 following a wave of criticism directed at the company, before recovering.)

K12 leaders said a number of factors were behind that lackluster enrollment numbers, including “the company’s inability to convert the increased volume of student  applications into enrollments at a level achieved during previous years due to performance in its enrollment centers.” 

To a lesser degree, the delayed start of open-enrollment periods for some schools also contributed, the company said. K12 officials were scheduled to hold a conference call with investors late Thursday afternoon, after the market closes.

The for-profit company, which operates schools in more than 30 states, has become one of the most controversial players on the education landscape. Critics have accused the company of placing a higher priority on growth and generating revenue than producing strong academic results. K12 was the subject of a lawsuit by investors who accused its executives of putting forward an overly rosy assessment of its academic performance to boost the company’s stock price.

In a number of states, the company has emerged as a focal point in debates over the for-profit sector’s involvement in elementary and secondary education.

(See Education Week’s past coverage of criticism of the company’s business model, complaints about its practices in local districts, and K12’s and other for-profit companies’ efforts to win friends and influence policy in state legislatures.

Most recently, K12 was the subject a stinging analysis by prominent hedge-fund investor Whitney Tilson, who questioned its business practices and said its stock was overvalued and headed for a fall. Tilson described K12 as his “largest short position.”

[Update: In Thursday’s conference call, K12’s Davis acknowledged that the company had made serious missteps that led to disappointing enrollment numbers, but he argued they were the result of management mistakes—not slippage in demand for the company’s core services.

K12 Inc. officials forecast that their revenues would increase by between 3 percent and 4 percent for the first quarter of fiscal 2014, which is lower than the company’s full-year growth, and that they would also incur operating losses during that period of $8 million to $10 million.

While K12 “is not abandoning the goals we laid out earlier this year,”  Davis said on the call, “our execution simply has to improve.” He added: “We understand we didn’t deliver. This is on us.”

Company executives said that applications for enrollment in the schools the company manages had risen, which K12 views as a measure of burgeoning demand. Applications climbed 11 percent for this year’s enrollment period, the company said in a statement released to coincide with the call. But K12 officials cited their “inability to convert the increased volume” of those applications into students who actually entered K12’s schools as a factor that held back enrollment.

Davis blamed K12’s struggles in that area on an array of factors that company officials either did not anticipate, or did not adjust to rapidly enough.

K12 did not have the correct staffing in place to enroll sufficient numbers of students in its schools, he said. In addition, increased state requirements for online education providers, delays in opening certain schools, and the company’s delays in promoting its schools also brought setbacks, he and other K12 executives on the call indicated.]